We've visited quite a few National Parks over the years. When we were younger, we found inexpensive cabins available within the parks where we could bring our kids and enjoy the natural beauty, fully supported by a knowledgeable, patient, and friendly staff of Park Rangers.
But the National Park Service (NPS) has not fared well in terms of budget during our lifetime. Instead, Washington has insisted that more and more Park services be contracted out to concessioners. Denali National Park perhaps represents the ridiculous extreme created by that policy. In effect, except for campers, the Park has been surrendered to package tour operators.
Mount McKinley National Park was created in 1917, in response to some well-connected hunters who wanted to protect the game (principally Dall sheep) 
Buses, public and private
from "commercial hunters." Initially it was a wildlife preserve in which hunting was allowed under NPS control. The original Park limits did not even include all of the mountain. A single gravel road led back to the Kantishna gold mining region through the Park.
Access to the Park was principally by the Alaska railroad, and visitation was low -- only 44,000 in 1971. But that all changed in 1973, when the George Parks Highway (named after a territorial governor) was built in 1972. The number of visitors skyrocketed to 570,000 in 1987. Somewhat inexplicably, it has steadily declined since then, and was below 300,000 in 2000.
The boundaries of the Park were greatly enlarged (and the name changed) in 1982, but Kantishna village, which had developed some exclusive private resorts, was allowed to remain under private ownership. At least one of these lodges charges $660 per person per day for a "wilderness experience."
There are a limited number of campsites within the Park boundaries. These may be reserved in advance, and would appear to be a good way to visit the Park. But by far the majority of Park visitors are forced to stay outside the Park in expensive private hotels and to take expensive bus tours with private tour guides in order to see the wildlife (which is visible for free elsewhere in Alaska.) While it's possible, on a few clear summer days, to get a good view of Denali from the Park Road, to experience the mountain requires either a climbing expedition or the mountain sightseeing flight such as we had yesterday.
Here are a few specific data points: the Visitors' Center was open only from 10:00 a.m. to 4:00 p.m., even though there are 19 hours of daylight today. There is no sign in front of the Visitors' Center telling visitors what to do when the Center is closed, e.g., where to go for information or tickets. The Park Hotel looks like a disaster; 2001 will be its last year, when it will be torn down, leaving only campgrounds (and the private Kantishna resorts) within the Park boundaries. There are no interpretive nature trails. [There is a sign for a Savage Cabin Interpretive Trail, but we walked the whole trail without seeing a single sign.] Only 15 miles of the 93-mile park road are open to private vehicles; the rest is open only to licensed tour buses and shuttle buses (of course the buses to the fancy Kantishna resorts are also allowed to use the park road.) In those 15 miles there are 14 pullouts. One of them had an interpretive sign with a picture of park visitors in 1926 (they dressed more formally then); the other had a panorama naming the visible mountains (Denali would have been barely visible on a cloudless day, which today was not.) There were no signs showing pictures of the wildlife the visitor might hope to see, describing the geology or other Park features along the road. (If everybody is on a guided tour bus, you don't need signs, eh?)
We conscientiously drove 15 miles in and 15 miles out. We saw one snowshoe hare (tame, around the Visitor Center), two willow ptarmigans perched atop stunted spruces, and a small herd of caribou. We also saw fur by the side of the road where a snowshoe hare had been killed and eaten by a predator. We 
Scheduled to be Torn Down
saw absolutely nothing to make us feel that the NPS wanted us to feel welcome and enjoy OUR PARK.
We passed many crowded tour buses. The seats are close together, not like a comfortable traveling bus. We stopped at one of the concessioner's hotels outside the Park where middle-aged Type A men were queued up and arguing with the staff about both hotel accommodations and tour bus reservations. It didn't look like fun to us, but as our readers know, we are independent travelers and don't take kindly to guided tours.
On our way out of the Park the Visitor Center had just opened, so we went in. The orientation film was perhaps the worst Park orientation film we have viewed: Come here if you want to see some wildlife. There was no information on wildlife management in the film. And inexplicably, it ended saying that maybe the hiking tourist would see wolves bringing down a caribou or a brown bear catching a squirrel. Such possibilites are (a) highly improbable and (b) unsafe for tourists. There was one harrassed NPS ranger, several long jet lines operated by the concessioner for wildlife and shuttle bus tours, and a bookstore run by volunteers. Finally, we found out that since the high season had not started (that begins Memorial Day) we could have driven 30 miles into the park with our private vehicle instead of 15. Needless to say there were no signs or information anywhere to indicate this - either along the road, or in all of the Park's printed information.
We had asked some questions about the National Park elsewhere in Alaska. Nobody could explain why it had to be a National Park; the mountain is in the National Forest. Nobody could tell us what there was to do in Denali. A couple of people suggested Talkeetna instead. Clearly for people who come to Alaska on package tours, they will be taken by bus or train to an expensive (and probably garish) private hotel outside the Park, and driven in and out of the park on a crowded and uncomfortable bus, where they will see some caribou, possibly some sheep in summer, and maybe a bear. They can then say they've "been to Denali."
But for people like us, we recommend taking the flightseeing tour of the mountain and forgetting about visiting the Park.