Gavin used limitations to resolve the O(n^2) validation time problem. Namely limiting maximum signature operations to 1.2 GB per block. As a benefit it would not be possible to O(n^2) attack even current 1 MB blocksize anymore with up to 10 minutes CPU validation in some cases - even segwit dont solve this possible O(n^2) attack on 1 MB blocksize. So the breaking of Bitcoin due to O(n^2) is not censorship, but FUD because your avare of this Gavin solution to my knowledge.
Gavin's sigop limitations didn't "
resolve the O(n^2) validation time problem" they merely
avoid it via a particularly ugly, non-future-proof kludge.
Segwit solves the "2+ minute troll block validation" problem by enabling Schnorr (and resultant tree) signatures.
*takes off pedant hat*