Smart crowds can be good or bad, it all just depends, but what it depends upon can be just about anything. As I mentioned in the thread regarding the Brooklyn fans' reactions during the Divas match on Raw this past Monday, it was both classless but also an example of some Divas needing to grow thicker skin.
There's nothing automatically wrong with being a "smart fan" in my opinion, all of that post on these forums are "smart fans" after all, but I think that when you become too "smart" for your own good to such a degree that you let it affect your enjoyment is when things become a big problem. If you spend your time watching wrestling, whether it's WWE, TNA, ROH, New Japan, some indie show, etc., to primarily point out flaws, critique what goes on & how you'd have done things differently, all you usually wind up doing is ruining things for yourself. That's not to say that you should just mindlessly lap up anything that's put on your TV or that you should just embrace every single angle, storyline, match & wrestler; you can still easily talk about some aspect of what you saw that you didn't like while still being a fan and talk about what you did enjoy.
A crowd like the Brooklyn crowd is difficult for any wrestling company to prepare for because it's sometimes impossible to determine how they'll react. For instance, the Divas have all gotten very positive responses from the fans up until Monday, yet the Divas received a good response from the SummerSlam crowd the night before in the exact same arena. Also this past Monday on Raw, I was expecting that crowd to give the 8 man tag team match the business because it had a good number of frequent targets of smarky audiences including Orton, Sheamus, Big Show and Ryback, yet the match was also well received as was the singles match Sheamus had against Orton at SummerSlam the night before.
Sometimes, the reactions of such crowds can genuinely help companies determine in which direction they should go in terms of who gets pushed, storylines, angles, etc. while other times it seems as though those crowds just decide to dump all over a show just because it feels like it. There are also other times when really hot, smarky crowds are genuinely there to enjoy the show rather than try to hijack or sabotage segments of it. So yeah, smart crowds can sometimes be all over the place.