I guess the big problem that we could have that makes the stadium issue an ongoing concern is NYCFC being the secondary tenant necessitates that our schedule be subordinate to the Yankees schedule. We've seen what happens with that this year, as we have these periods where we've got long home stands followed by long road trips that can be frustrating. The big worry for me though, is what happens when the Yankees and NYCFC make playoff runs simultaneously. Granted, the MLS Cup match wouldn't be affected, but what if we had to scramble to find a last minute venue for a playoff game because the Yankees are in the World Series? (Yeah, we're a few years off from that possibility, but it could certainly happen in 20 years)
That's beyond the issue of making numerous public statements affirming their commitment to finding a stadium space as soon as possible - as long as they're making a good faith effort I'll hang in there, but if it starts to appear that they may not be I'll be more willing to use my season tickets as what leverage I have to show my discontent.
(Sorry to pick you out here - sounds like we're generally in agreement, but I would put more emphasis on the importance of the building as it allows the team to take greater control of its own destiny.)