Here's my two cents: You shouldn't be dumping your stuff in group galleries without justification for them being there. At best, it gets some attention, and at worse, it gets removed and you get reprimanded by the owner. Instead, market yourself to the owner of the group. Tell them why you think they should add it to the group collection. Make them want to display your work. It'll be much more satisfying and you'll get more positive reactions.
I am fine with group limits. I am fine with being rejected by groups. My problem is that when I go to submit stuff I don't know what those submission rules are. That is my problem. Stop taking me out of context.
Nah, I just like to be politically correct every once in a blue moon. Until I realize that calling them doodles is insulting to doodles, as this guy has probably spent quite some effort on that crap of his. At the very least with doodles you can excuse yourself by saying "well shit, that only took like 1 minute".
Limits are reasonable for the most part. I have a friend who complained about some big groups that only let you submit one deviation every few months. How many deviations were you trying to submit though? Because even if they didn't directly give a limit, you still have to be reasonable. Personally, I get annoyed if I see more than two deviations by the same artist submitted at the same time. At least spread 'em out over a few days or so.
The point I'm trying to make is that submitting a lot of images to a group actually reduces the chances of anyone looking at them, which defeats what you're trying to achieve (publicity). If I see that an artist has spammed a group I'm in, I'm more likely to instantly delete everything than actually look at any of it, and most people share that attitude.
With regards to the specifics you're complaining about; maybe many groups don't specify their submission limits because they assume their members will be modest and restrained enough not to need telling.