That lot is wider than it is long, whereas MK is longer than wide.
It doesn't feel big when you reach the road, but if you have my luck and always are parked at the outside of the lot, then it feels very large.
But I personally never use the tram unless it is sitting there waiting for me in any of the parks, and I am there pretty much every other day. 100 acres has become normal to me, though I get that it's not for many people. I also grew up in a major metropolitan area outside of Florida, so I'm used to paying to park for anything with much more volatile prices than what Disney offers - at least their surge pricing is optional.
If people are willing to pay $15 to save a few steps at the end of the day, more power to them. They help pay my salary so I'm not too worried about it