So Bitcoin's security depends on the dev team spotting and educating the malefactors? But if the intent is to harm Bitcoin (statist gubermint thugs, Saurian Bankster Jewesses, etc.), wouldn't they laugh at the devs' friendly advice?
What would have been the outcome if the misguided Bitcoin company ignored devs' advice & said lolno, we're putting up more nodes, don't cost us shit?

Simply deploying hundreds of nodes without active users securing them with economic interests isn't extremely dangerous in itself because wallets still check for the longest PoW chain and not just the rules from the corresponding nodes. It is dangerous in a sense that those nodes could falsely give the impression that our ecosystem was more decentralized and it could introduce some potential non-consensus bugs but any nodes that were compromised and didn't follow the consensus rules would simply be an ignored alt.