I respect the effort he's put into right to repair, and agree (in general) with most of the points he makes about it.
But I also think he's an asshole and we need a better voice for the RtR movement. I've seen him get into fights and strawman people on reddit as corporate shills just for calling his attitude abrasive.
More customization = Higher chance something breaks.
Admittedly, chances are it's just something minor like your icons looking weird or transparency breaking, and it's not like it happens very often. However I have had it happen while I'm trying to focus on something and it's definitely an annoyance I could do without.
I like that I can customize on the off chance that I need to fuck with something. But defaults have been getting better and better so i've done it less and less.