Why do they do this?

I was at a fairly tight 1-2nl table. They are all pretty tight comapred to last year, but this was a Saturday night.

I had 88 in middle position and made it ten to go. 3 players called. This was one of the larger pf pots. The flop came Kc 9c 8h. The bb donked 10$ into me. One player folded. I raised to $30, the other guy folded and then the bb folded.

Why did he lead for ten? My raise didn't really give him any information. He might be trying to tease in a draw but he was getting fine pot odds to call the extra 20 and did not. If he would have check-raised like a normal person I would have made much more.