I think this is because of the sketchy way in which passports for various tax havens, Caribbean countries, etc (not mutually exclusive) have been sold and bought and those passports allowed visa-free access to the EU. The corruption in those countries puts the EU borders at risk, hence these new rules. Sauce: https://www.occrp.org/en/dominica-passports-of-the-caribbean...
It's a tit-for-tat response to ESTA.
Imho it's just another McKinsey idea.
How i envision the discussion:
""" - Most of our illegal immigrants entered legally within our borders, quick find us a new revolutionnary idea!
- Hey, we have this ETIAS idea. bla bla.... .... bla bla... So it's nothing at all like ESTA at all (two hour presentation)
- Nice, here's 5 million """