Don't know why, but I haven't had a single crash. Maybe it's people on Windows 7? The game's optimized for Windows 8.1 iirc, which is what I have now (just installed it a couple weeks back specifically for BF4).
Still sucks though, lots of people frustrated at losing exp from their games crashing. But it's a huge game, and like any other at launch, the first two weeks are going to be insane.
Protip:
If your game crashes during a really good match and you don't want to lose all the experience, do not join the server again before it switches maps and the game's recorded in Battlelog, otherwise you'll erase your previous history on the server. This is only if it was your game that crashed though, if it was a server crash, everyone lost all progress made during the match. If you join the server again once the new map's started, all the previous exp from the match before will have been applied.