the 45 second timer excuse is a cop out you can converse when its your opponents shot....
they could but why should they have to?
Maybe they aren't chatty.
Maybe like myself they are sitting in a cigar bar and chatting with the people around them while they play.
Maybe they are dealing with spouse and kids chat or activities or issues.
myself i'll often give a greeting if they give one first. but after that I'm silent unless it's someone i play alot and know a bit more.
to get mad because someone won't answer you is rather narcissistic.
if it helps... i rarely even look at the name of the person I'm playing. I've been known to look at it at the end of the game and realize it's a friend.
nothing wrong with not being chatty.