I'm not suggesting that we should disable every single limit most clients have by default, but I'm just curious to know when we consented that line. Because as far as I know, developers drew a line in non-standardness and users followed later on without much debate. For example, what's the explanation behind the limit of OP_RETURN at 80 bytes by default?

Furthermore, standardness being what safeguards the system is flawed in the first place. Consensus rules protect from whatever. There's nothing stopping a group of miners from setting up a market, or just sharing their node URI, with NFT users, wherein they bypass the non-standard rule of dumping transactions with Ordinals etc., normally having their transactions included into blocks. And that's even worse, because now regular users don't see how much filled the mempool is, and the fee they select will not correspond accurately.

In fact there is pretty much only incentive for miners to disable most non-standard rules.