Yeah, but in Fertitta's mind, it's "how long does it take to make the money BACK?" If you're making $25m a year running a hockey team and it costs $800m to a billion, you're making your money back in 20-25 years and he's 67 years old. (And that's a made-up number, as many on this site would probably love to argue hockey in Houston would not be THAT profitable!)
Most profit is made on selling the team a decade or two later. But he can't JUST sell the NHL team while maintaining ownership of the Rockets/control of the arena, because no one is going to want a tenant asset (hence the Winnipeg Jets 2.0).
So that's why he's always been interested in $200m-$300m "buy them and move them like the 1990s" team, but not a $500m to $800m or more "modern NHL expansion/relocation fee team."
Partnering with Friedkin accomplishes the financial goals of "also owning an NHL team" while not tying the Rockets and an NHL together. Obviously, he wouldn't get AS MUCH directly; but there's also indirect aspects.
They can structure the like three separate deals they need to make (arena management, minority share, and TV) so it's win-win. While Fertitta would be "giving up" revenues from inside the arena by not owning the team, he's gaining revenue on the Space City side of things from selling ads to 80+ more games. The money Feritta is "leaving on the table" is being picked up by Freidkin, who's leaving money on the table that Fertitta picks up.
Throw in that he WANTS to bring a WNBA team to Houston, too, and that'd take arena dates away in the summer, but if he's controlling half of a second arena...
You're right about the "45 of 365" aspect, but not all 365 dates are equal business. WEEKENDS are just more lucrative than weekdays.