I wholeheartedly agree with you. The Direct IM implementation on Adium is very iffy, as is the one on iChat. So are groups. If someone on Windows wants to quickly send me a picture or invite me to a group chat, I have to deal with Adium's shortcomings.
I had much fewer problems when there was a native version of AIM for my computer. In fact, I used to use my old iBook G3 for AIM just for that reason (until it got too unbearable). All you snarky people out there-- just because Adium works fine for you when you're chatting with your friends doesn't mean it works for everyone.
A lot of people worked very hard on this. Considering it's a Mac program, there's a good chance at least one of them is a member here. How would you feel if you worked for months on something and you came to this forum and found people tearing it apart for no reason?
All you negative people need to take a rest. There are good reasons to hate AIM-- ads, bloat, spyware... but they haven't presented any of that in this program, they've just provided a little alternative, and hopefully, some competition that will make things more interesting.