Most if not all Arch devs are likely advanced users, they didn’t need to maintain a user friendly installer for themselves so the old one got out of date and was removed.
What’s probably changed recently is that Arch has grown enough to get devs/trusted users who actually wanted to write and maintain an installer, so now it has one.
I find the Arch dev justification/perspective for most things much better than many users on the forums who tend to pick up the basic idea and cargo cult it whilst losing the context behind it.
It can be hard to resist some analysis paralysis when faced with an incredibly broad problem. There's a strong urge to find one solution to cover all cases. Trying to do everything at once being so overwhelming that it's impossible to get even started on it.
Of course, you're correct that the best thing to carve out the most common cases and then iterate. I've found that it takes time and experience to gain the wisdom to learn the perfect is the enemy of the good.
it has an installer again. maybe the userbase will change.
[0]https://wiki.archlinux.org/title/Arch_Linux#User_centrality
An installer, if anything, improves "user centrality" because you're making it more accessible and usable to most users with just the most common few options.
Not having an installer improves "dev centrality" (the few users who matter are the devs and other advanced users), over and against user centrality.
You could use the same thinking to argue against having a package manager. You might have to install a package manually anyway, so why bother providing packages at all?
There are other distributions that focus on other things and people can choose. If Arch chose to implement lots of convenience functions, that choice could be to the detriment of other strong aspects of the distribution.
This is a cop out. An installer doesn't need to cover every option a user might want. An installer only covering popular options/configurations is only a problem if the installer is the only way to install the system. If it's just an option itself during the install there's no issue. The weird corner case can still be handled manually while more common options can be handled by an installer.