It's a $10 donkament so you will see people call with all sorts of garbage.
Some people have the mentality that if they put money in the pot preflop, they at least have to see the flop, regardless of the fact that their current investment in the pot is very small and they are getting a really bad price to call the shove.
Also, some people cannot bring themselves to fold suited cards or hands that have a king (or ace) in them preflop.

If you were making a move here and just trying to pick up the pot, you'd have to be more concerned with your opponent's tendencies and whether he is likely to call your push. Most people will limp their bad hands but will not risk half their stack on them.

But of course, in this case, you're pretty happy to get called here, you just wish he didn't suck out. Nothing you can do about that.