Why some players avoid continuation bets on UB 10/25, 25/50?

[Diesel]

Besides Aplusgame(who makes it very frequently), Green plastic(and Fishtank) few players use it, even in position they just check and let the other guy take the pot from him. Bruiser dont use it often either, rednosesam also is cautious. I can understand that if their playing some party 200NL because the play is so terrible they will call with anything resonable but wont good and decent players fold more, its 2/3 that he missed after all, can someone explain this?