The average number of days per skier is 6 which means there are lots of people that do not even ski enough to warrant a season pass.
Most season passes are designed so that 7-10 days and you break even. With the Epic Local Pass, break even is around 4-5 visits - no brainer - we got 35 days on the pass and 5 days off the pass! If a family skis a lot, I think a bigger reason for not buying a season pass is to not get stuck to one resort. We had passes to Cannon Mountain in NH and our whole family cost about $2000 at the peak for 5 of us we are now down to 3 and about $1900 for Epic Local. There are many economical pass products out there so I do not get the thought of not getting seasons passes. I used to deal hunt (tracking costs) and in the end spent just as much on lift tickets if not more - the difference was - the dollars are spread out.
This an invalid generalization - I have been skiing for about 40 years, often the deal hunter, but the past 5 years I have been a Season Pass holder that "day trips", and with a multi resort pass do not have a locker, I do not pay for parking at Keystone, Breck, A Basin, Loveland and others (Vail and Beaver are exceptions), we as a family also do not do season long programs, we also bag our lunch and bring our beverages (adult variety too), but do eat at the resort from time to time where the restaurant is not owned by Vail. I work with lots of locals in CO that do the same.
When living back east, parking never cost anything, living in NH - we day tripped all the time to approximately 20 destinations and got 50 days in each season with 20-25 or so days on the pass. Many that I skied with in New England were not any different.
One final point most on this site are not average skiers and probably get way more than the average of 6 days in.