Well sure, some people will call you evil for choosing GPL over MIT.
But the developer community as a whole, which has already shown themselves to be basically fine with proprietary software existing, is not going to be thrown off because you call yourself Source Available.
And the people who would judge you for choosing a Source Available license are not going to suddenly be OK with you using SSPL just because Mongo says to call it Open Source.
I don't think this is true. Lots of people will call anything other than their preferred licenses evil.