I try not to be too negative toward GW, because if people enjoy it that good for them and I find 40k tournaments are a great way to get people to consider other games. That said, looking at what GW did in a similar situation and worrying about another company being that bad at writing rules is probably being excessively pessimistic.
Simplifying and streamlining is probably a good thing, if done well. AoS was not really a simplification, it was starting anew with an entirely different game. 40k 8th edition is more enjoyable (and popular as far as I can tell) than 7th. 8th is mostly awful for the same reasons as 7th was (rules being an unbalanced mess), but at least the game isn't such a pain to play.
Which is what "streamlining and simplification" is about; when done well. It's about minimising the things that one has to do in order to play a game, but that are not part of the fun we're after. Things like measuring, looking up rules, learning rules and making lists (fine and fuzzy line between fun and chore there). Like peeling fruit isn't what you're looking for, but you need to get past it.
More rules don't make a game better; good rules do. The easier it is to get to actual playing and resolve things the better.