Only because everyone aimed too low. NACS (as mentioned before) doesn’t cleanly support adapters or detachable cables. And CCS Combo 2 is unnecessarily clunky. And you end up in a rather awkward position if you ship a car from the EU to North America or vice versa.
It ought to be entirely straightforward to design a standardized cable, NACS at one end and with a new interface at the other, that can attach and detach from a compact and weather resistant charge port. It would be fully compatible with all NACS vehicles, and it would achieve this by negotiating voltage and current limits with the EVSE at the other (newly specified) end.
It could even be cheap in a low-current version — it would basically be an extension cord, with two 12AWG hots and a ground plus a couple of little wires and the whatever inexpensive electrical parts are needed to declare its capabilities. If you can buy an e-marked USB-C cable for a few dollars, the latter won’t cost much.
Shipping a car between the USA and Europe is an extreme edge case for wealthy people and the marketplace can solve for the issue of adapters and dongles where the need arises.
(For reference, I'm in a CCS2 marketplace.)
When Tesla later engineered the European Model S, it needed three-phase AC and adopted a modified Type 2 connector, which fitted behind essentially the same tail light door.
But that’s all history now.
Arguably both markets ended up with good solutions for their needs: NACS is exceptionally compact and well suited to North American single-phase AC plus DC fast charging, while Type 2 is larger but supports Europe’s widespread three-phase AC.