I'd imagine this might mirror yr real-life experiences. If you're an introvert who occasionally makes deep connections, then, surprise!, you'll probably have a few lengthy pm conversations every nowandthen. Etc.
In real life I talk a mile a minute, make friends really fast, tend to read people really well, but am always flitting from convo to convo. Guess what happens here? LOL.
I wouldn't worry too much about it, I have been a member for several years, and while I do enjoy posting occasionally to questions, and I have had a few positive exchanges on this site, I have never been propositioned by anyone to communicate any more than through this site, and while I confess I would be intrigued by such an offer, I'm certainly not losing any sleep over the lack of offers either. I enjoy this site and offering help where I can, but I have many other things demanding of my attention than GAG.
It's normal and not weird. GAG is meant to be a place to ask questions and give opinions. Messaging is only auxiliary just in case someone has a lengthier conversation regarding their question with a particular opiner :)
No... Not everyone is for the same here. And it also depends on your personality and real life experiences... I wouldn't think much about it. Iif there is no one here you are interested talking to just don't do it