"if you really think that a 17u player needs to stop practicing to just play is way way off"
I never said that. You must be arguing with someone else.
The issue is not whether a player stops working to improve. Players should understand, that never stops. But a lot of the game is actually bringing together 9 guys with individual skills. Players need to work on their individual skills, well, individually.
The team does not need to get together for players to work on their conditioning, fielding techniques, batting, or bullpens. To the extent that someone is looking to do their individual work only when the entire roster is all there together -- the way you would with a Little League team, a high school team or even some travel teams -- this would be atypical for any high level 16-17u exposure team. That is because an exposure team has a different purpose from a recreational team, a youth developmental travel team, or even a typical high school team. If you want one of the latter, you have my blessing, but don't fault an exposure team for being exactly what it says it is and not something else.
There is a certain amount of work a team does have to do together so that you can run pickoff plays, cutoff/relay plays, etc., as a team unit. We do get that done as and when we are able. And of course, in pre-game warmups and constantly during games there are many reps and "teachable moments." We would never suggest that any of that should stop.
As I said, our team is not what every single player is looking for. So, consider what you need in your individual situation, examine the options, and then figure out which one best suits you.