I enjoyed this post from Idle Cartulary on their blog, and I feel like the vibe is kinda one that would fit here, essentially 'there's design preferences and having them doesn't make you morally wrong'.
Can't count the number of times that I've bumped into people who've been convinced that There Is One Correct Way to play, which is really funny to me. Anyway, I thought it was a neat way to say 'people are going to want different things from different games', which I really wholeheartedly agree with, and wish more people would talk about with their groups. I swear this is why many groups end up fighting - because they're not clear about what they're expecting to get out of the game or the style of the game before they start playing, and when that tension is revealed later, it causes arguments.
I don't know if I agree with the assertion that there's no such thing as bad design, but my disagreement is more nitpicky than anything so can probably be ignored - I'd call it bad design if your DM book says 'this book will help the DM run games!' and then is layed out or written in such a way as to obscure that goal. I see that as 'game design' as much as 'this is the way that you make characters' but I think that's just a difference in term definitions more than it is a disagreement on fundamentals. Is 5e designed badly if combat takes forever? Nope, especially not if you're one of the people who enjoys it.
I wish I could remember who pointed it out (it was in the last year or two) where in a review of the original Little Black Books for Traveller, the reviewer noticed something about what Marc Miller had written back then. "Play" in that ur-Traveller included just rolling up characters and making subsectors for one's own entertainment, among other similar things. This was a revelation to me, as personally I don't actually play the "A bunch of players get together and send their characters on adventures" very often. I've always played through creating, but had never thought of it as the same quality of thing as the dominant paradigm.
If play can be encapsulated by something that far away from what people normally think of, it makes the idea of "one true way" that's in turn a subset of tabletop play even more ludicrous -- no pun intended.
Which again moves into the territory of the question if RPGs should really be thought of as games.