You give one map to any playerbase that has a repeatably reliable rate of return (RRRoR?), and someone's gonna farm that like being Amish is goin' outta style.
You look at the Mission Architect, and you see farm tools. Maybe, but most established farming cartels go with what they know, primarily because of the time invested in their builds to maximize their effectiveness on the one farm map they can do not only in their sleep, but while they're on the can or cyb0rzing. That's not to say they won't expand in that direction; it just doesn't give them anything new (beyond a few exploits that have already been, or will be, addressed).
I look at the Mission Architect, and I see a wealth of user-created utility. Drama, comedy, build optimization test arenas, co-op hero/villain expansions, a chance to build a Freakshow mish where they all talk in l335t-5p33k haiku - everything.
Players, for the first time, are standing up and exercising their comic book creativity for the masses. The Architect is pretty flexible; you can make custom opponents; custom arch-villains/heroes; dialogue up the wazoo;
hundreds of environments; a mission search utility that, while it can be improved upon, is certainly functional; player ratings for the gamers themselves to use in rating mission quality (and yes, that can be abused, but I'd rather have it than go without).
The Devs are idiots? Are you mad? The Devs just gave me a chance to write for a playerbase that I love, and that playerbase is responding in kind. The Devs aren't idiots. They're pioneers who got it RIGHT on this shot.
If you're too blinded by "omg i haet frams!!", well, I hope they have Zoloft on your Bizarro Earth.