Something called a CUA (Conditional Use A-?) lets companies like the Institute and other folks run a trip or two per year on Rainier. So it can be legal . . . I think they have to do the Emmons or the Kautz. No DC/Ingraham.
Yes, trips on Rainier sell out quick for all three companies.
Bucket list folk . . . they generally all get their assses handed to them, even when they do summit.
They like the cycle as they generally have little to no mountain experience whatsoever (but think Rainier is their gateway to the Seven Summits!). . .