Public test environment only accomplish three things. - Primarily allow Developers to test changes [i]without[/i] upsetting the existing balance of the live servers. - Let Developers to get their feedback sooner. - And for really impatient people to get to play the changes sooner. The balance of the live servers is not so delicate that it needs to be "protected" by a public test environment, unlike a game like Overwatch which very much wants to be an e-sport. Altering a weapon's damage by 4% is not something you need a PTE for. Radical changes like alterations to the sandbox or redesigning Viking Funeral are more suited to having a PTE but these kinds of changes are rare. There's also a matter of progression. Destiny is a game very much about what you have. It's inevitable that people will complain about stuff they have on the live servers not transferring to the PTE or vice versa.