I agree pretty much completely. A perfect game with no population still isn't a lot of fun (and we are far from perfect.. or fully functional..), and considering the negative PR around this game, I don't know if a second wave of players is ever coming if it hasn't yet. It's a truth I think I'm starting to accept, though I have been having fun with the game, the small issues still keep me from fully embracing it (lack of map/gametype variety being the biggest).
Here's a mad scheme for "fixing halo": Windows 10 is on the horizon, promising increased cross-platform play with the PC. Gamers in Russia will have access to a free-to-play Halo later this year, while nothing has been announced for PC gamers in other countries (hence, the hacked together El Dewrito that has been a surprising amount of fun). Microsoft knows the lack of Halo on PC pisses people off, they aren't that stupid; but this Russian leak also serves to assess the demand for a Halo PC, which is pretty high. And we know a free-to-play Halo with pay-to-win elements would be crucified in the Western markets. It's surprising how little Microsoft is going after these El Dewrito devs.. perhaps they have a product that will make Dewrito obsolete in the next couple months.
I wouldn't be shocked to see Halo MCC announced for PC at E3 to release alongside Windows 10 to promote cross platform play as an attempt to inject the community with more players and ramp up the Halo 5 hype train. Keep Halo 5 Xbox One exclusive (releasing MCC will create demand for Halo 5 in a market not exposed to a new Halo campaign in 8 years). The MCC is no longer a system seller; releasing these 4 games on PC would exponentially increase the size of the community, garner the goodwill of pretty much all PC gamers, and (perhaps) could INCREASE the long-term demand for an Xbox One (# of PC gamers interested in console for future Halo titles > # of those that would buy XB1 for MCC).
The only major problem I keep thinking of is keyboard/mouse vs. controller issues. Perhaps could set matchmaking by input method (since PC is getting wireless XB1 controller support..), I don't know. This is all just a pipe dream anyway; it's too smart and too consumer friendly to ever happen. But this is the kind of dramatic thinking that I think will be needed to rebuild this community... if 343 and Microsoft even care enough to do so.