The reason why Whitney is being considered over Community isn't because of the relative qualities of the show, it's mostly down to its ratings. Community gets a 1.6, which would've gotten it cancelled in its first season on any other network, but NBC kept it around because a) the people who like it, really like it and b) they had nothing else. Whitney, with Community's terrible lead-in pulls a 1.9. Not much better, but when you consider that everyone who's going to give Community a chance has had 3 years to do do, while Whitney still has a chance to break through, it's not hard to see the arguments made by TV executives.
We shouldn't be mad at NBC - I'm sure they'd love to see Community succeed more than we do, it's just a pity that more viewers don't feel the same way.