I'll speculate that the advances in ski technology have made Jackson a bit more accessible to vacationing skiers. I'm pretty sure JH's increases in skier visits have been going on for over a decade now. When I was at a journalist meeting in 2006 they were saying then they were on track for a record, likely to hit 400K visits for the first time. So if Jackson's then antiquated lift system was not producing big lines and choke points in the 1990's, I'd say attendance was a lot lower than in 2006. Then we had the 2 seasons without the tram. I suspect management decided to invest in lift upgrades, wanting to retain the gains in attendance over the final decade of the old tram.
Hopefully Bob or someone else here knows the actual JHMR attendance figures over the past ~20 years or so and can confirm or refute my speculation.
Of course, my pet peeve in skiing. Thankfully I live in one of the few places where that mentality is weaker, and there are enough of us in SoCal to support Mammoth until the snow runs out.
That certainly is the opposite of the alarmist conventional wisdom, and equally wrong. There's huge volatility in snowfall early, mid and late season, but over the period we have data, 40+ years, no trend of more or less snow, shorter or longer seasons with natural coverage, or incidence of extreme seasons either high or low.
I suspect most ski areas monitor this more carefully than they used to. In Mammoth's case, there is now the pressure of debt load, but also a long history of late season operation. Mammoth is unquestionably profitable and in full lift and terrain operation through the weekend after Easter due to some CA school breaks. After 3rd (occasionally 4th) weekend of April a few lifts that service up to half of terrain remain open. Extra lifts run on weekends to accommodate the continuing weekend skiers from SoCal. The 3 day weekends at Memorial Day (open 90+% of seasons) and July 4th (30%) are very popular and profitable. Mammoth recruits race camps to pay the bills midweek in May/June, generally knowing by March how long the snowpack is likely to last. In 1983 (July 28) and 1995 (August 13) Mammoth stayed open even later. With similar snowpack in 2011 they closed on July 4 because they could not get more camps to come after that date.