This is my page about my policy on implementing WP:3RR and stuff.
Currently, it is a work in progress. You may not quote this.
Why edit
I got blocked for 3RR quite a bit in the old days (I can even remember *before* 3RR was formalised). So it was one of my planks on my RFA. And I've stuck to it.
Blocks vs Protects edit
Sometimes on a 3RR report it is perfectly clear that one side is at fault. They get blocked. Sometimes, there are two people reverting hammer-and-tongs. Then I'd block them both, though some would choose to protect the page. Sometimes, it is a giant mish-mash of reverts and godd faith edits. Then judgement comes in.
In all cases I *prefer* to block editors rather than protect pages. Protecting the page can be seen as rewarding edit warring, and often frustrates good faith editors. Generally, losing decent edits to a page protected for a week is worse than losing the edits of whoever you would have blocked across the rest of the name space. The difficulty then arises in the rare cases that a known high-quality editor oversteps the mark. Perhaps they just get a warning. Very rarely (whisper it) admins may choose to protect a page in order to avoid having to block someone they really don't want to block.