The outrage is not directed towards Mills at all. It's what he represents.
So now SA has TP on the books (but injured).
Has Mills on the books (for a lot more money).
Has Murray on the books (no change)
Manu maybe retires and Simmons maybe gone (replaced by White & Hanga) .
In this scenario, a back court that we 100% know was no where near good enough is now worse by any objective measure (unless Murray leaps big time) is now more expensive.
If Murray leaps, that's great, but that is independent of paying more for a back court rotation that clearly was one of the bottom in the league.