this is not the case. i know last year they ran busses for all of the three ssc passes. the three major passes are sugarbush, stowe, and the triple major (bolton, jay, and mad river).
each pass has its pros and cons. stowe is by far the biggest, and has the widest and most creative selection of park features. it was my impression that most kids went with the stowe pass, so it's easy to find rides. however, in my experience, stowe is the most crowded and has the worst conditions
as far as the triple major, there is good and bad to each of the mountains. jay gets great snow, but it's the furthest from burlington (about 1.5-2 hours depending on weather). i've never been to bolton, but i've heard that the park is decent, they do have night skiing, but the mountain is small and the conditions don't tend to be great. and as for mad river, its reputation pretty much speaks for itself.
i've always gotten the sugarbush pass. sugarbush has two peaks, but i only go to the smaller one. it's not very big, and that's a problem for a lot of people. the park also isn't very big, but they do have a park lift and there's never anybody there (especially during the week) so it's easy to lap all day, and they have a decent amount of features in spite of the size. the bigger peak has slightly worse conditions, no park, and lots of gapers.
this is all of the information that comes to mind, but hit me up if there's anything else you need to know. it really comes down to personal preference/what your friends want to do. choose wisely, but if you get it wrong you've got three more years to get it right. welcome to uvm!