Though I could also point out that the original decision was 32MB per block, not 1MB or 4MB.
Yes, but 1 MB is what most of the nodes accepted.
IMO it's more likely Bitcoiner at that time merely went along with Satoshi decision to change block size to 1MB rather than consciously think and accept it.
The blog mention some good point, but "unstoppable" isn't accurate term. Miner and some node need to upgrade their software to activate the soft-fork.