To also play a devils advocate.
These are not a professional payed testers. It's the normal folks paying to experience what has been developed early.
Ofc, they want to support the company, so they pay for packs, but this doesn't mean they are also ready to do the professional testing job.
In addition, "most of" players that buy the packs, do not do this for purely noble reasons of "unconditional love" for game development they do it so they can gain advantage (by gaining knowledge about game and it's mechanics earlyer then players not in alpha/beta), so they could, when game releases, have a better start, and gain a better position in game community system.
There will, of course, also be plenty of players that will actually test the things out nicely and send a good useful feedback, but you can't expect that from everyone.
Also, not everyone is an experienced gamer, there will be "fresh" players coming, who do not fully understand the concepts of alpha/betta, and kinda expect almost fully finished product. Again, inexperience isn't their fault, everyone was inexperienced at one point in time. Most of them will learn.