This is how this community works. People nitpick until they get it right. The biggest pet peeve of this community is people rushing ICs/being unprepared, not fixing MINOR AND EASILY FIXABLE mistakes before posting IC, and the set/renders just being low effort/quality in general.
I think the designer admits that the nitpicking on kitting and other actual keycaps-related stuff is important. Behind the scenes, he's working very hard to fix and improve things based on constructive feedback. However, with that said, some of the feedback just seems weird like debating about the shadows cast in the renders by the keyboard? What's the point of that? How does that affect what the keycaps will look like? Another comment previously asked why the background red stripe was a different size relative to the other strips. It seems like it was just a design choice by the designer and the people who did the renders. If people don't like it, that's fine, but at the end of the day, those background stripes will NOT affect how the keycaps turn out.
Also, keep in mind that not every designer who posts an IC is super experienced. For many of them, it's literally their first time. There are no strict guidelines or rules about how to structure or post an IC on GH. So, it makes sense to just let the community vote on it. The best presented ICs will likely get more comments and views, which will likely lead to better and more feedback, which in turn likely lead to a more successful group buy. The ones that are more simple, will likely not receive as much feedback, which likely will lead to a worse potential group buy turn out if at all. People will just naturally learn and improve from this structure. It doesn't make sense for random community members to police this and force people to post ICs in a specific way if there are no written guidelines and rules on GH itself.
Finally, keep in mind that "low effort" is relative to your experience and age. If you're an experienced keycap designer and have launched many successful ICs + GBs on GH, then this might be considered low effort relative to your skillset. However, for someone else who just started learning about designing keycaps and doesn't come from a design-focused day job, an IC like this might already be a high effort for them. Age also matters. I learn much faster at my current age than when I was younger. Not everyone on Geekhack is an adult. The hobby has grown tremendously over the last few years and many of the new members are younger than people realize. I personally wish I was half as talented as they were when I was their age.
So in the end just think about how you voice your criticism. There is an actual human behind the design and post. Yes, the community benefits from rising standards, but I just do not see how it can benefit when members basically cyberbully other members disguising it as "feedback". Basically, what you say matters, but how you say it matters just as much.