Idk why developers refuse to use CTE/PTE. It just seems like common sense, especially on the PC platform. It's essentially free patch testing. All they have to do is fire up some more servers. Better patches = happier players = likelihood of players spending real money on a good product.
From my time as both a SrsGamerβ’ and game developer, I can tell you that if you see a recurring problem in game development that seems to have an obvious solution that's not being used --- it's probably that the solution is more complicated than it seems :D
In general, game developers are people who like to solve hard problems with creative solutions. So if there's a weird problem that's not being solved it's not for a lack of initiative or thought.
CTE/PTR is hard. It's complicated to get the right builds and the right people in while juggling player expectations and also delivering an experience which meets quality expectations.
That being said, we are always pushing for more ways to get as much feedback and hands-on time as we can!