Yep, completely agree. On a related note, I always find it odd that people rush to test the new endgame content on PTS of games. I mean, I understand getting a headstart on the competition and all, but I'd much rather wait until release and enjoy endgame on my actual character. If I played endgame content on the PTS, I'd just burn myself out that much faster once it goes live. Doesn't make a lot of sense to me...
You're not a hardcore progression raider.
In progression-focused groups, anything that aids progression is required. The serious ones will insist on PTR testing because it gives them an early shot at encounters they'll have to progress through later. This dramatically cuts down the time it takes them to clear that content and move on to hard modes.
World first competitors take that even more seriously.
Honestly, if you don't fall into one of those categories, then you don't need to worry about testing new content like that. Just get to it when you get to it and learn it as you go. No problem.