Every so often someone comes on here and starts a thread about the THS, and how bad it is for bowling. Usually they cite integrity, unrealistic scoring, and and guys spraying the ball all over the lane who shoot award scores.
Frankly I don't think any of the reasons usually cited for why THS is bad have much validity. I hear top level scratch bowlers complaining about a house hack shooting 300, and it sounds like sour grapes to me. Can you imagine a top level PGA pro complaining because an amatuer shoots 66 on a 6200 yard muni? Bowlers know what they are playing on.
Some people argue that the THS rewards bad execution. I think that is totally false. THS may not punish an errant shot as badly as a tournament pattern would, but THS rewards good execution ( speed control, release ).
So what is the only real problem with the THS? Until recently it was very difficult to find anything but the THS to bowl league on. For anyone aspiring to compete at a relatively high level the most important thing to learn is versatility. You can't learn versatility on a steady diet of one type of condition. When I was young we bowled on a lot of walled up conditions, but some were dead off the corner, and others had a ton of hold at 3rd arrow. That is how we developed a versatile game. Today people should play on as many conditions as possible, including house shots