I will chime in on this as being a coach that moved recently to South Carolina from a State in which there are no regular season OT's or PK's.
Problems:
1) You get a lot of teams that simply sit back and play 8-10 in the box the whole game and never come out. I know that you have some that do that here, but it is a lot more common with out the threat of OT or PK's.
2) And most importantly, You go the whole season without ever being able to practice the "TRUE PRESSURE" of a shoot out enviroment. I know that you can do you best to put stipulations on it in training, but you can never simulate what its like with the game on the line and fans in the stands. If SC changes to the no OT or PK's you will have teams season hanging on the balance of PK's that they never get to practice.