If we accept lighter baseballs as a way to get more home runs, what's wrong with corked bats or any other mechanical mechanisms that could be used to juice home runs? Sammy Sosa was suspended 8 games for using a corked bat, which was claimed was supposed to only be for practice and was used accidentally.

https://en.wikipedia.org/wiki/Corked_bat#History_of_use_in_M...

I suppose like any other sport, baseball is picky and arbitrary about what's OK and what's not OK when it comes to changing equipment and standards.