2) Ordinals/Inscriptions are just spam. It's basically a scamcoin using proof-of-attacking-Bitcoin as its "algorithm". Taproot witness data does not allow arbitrary data - that's just an abusive *mis*interpretation of script code that Ordinals is doing completely unrelated to Bitcoin. This _is_ a relevant distinction.
3) Satoshi introduced spam filters to deal with the spam issue. So Bitcoin literally _was_ designed to work this way.
4) Again, Bitcoin has used spam filters from the start. It is Core30 that aims to change Bitcoin by removing some.