Yeah box checking wasn't the issue there, just horrible design. Overwatch is a lot of box checking with some shit that really don't matter like making Tracer gay, Zaria having the butch lesbo pink haircut and such, and yet people really like the char designs cause a lot of them are just great. They also don't just do the stupid shit, you have stuff that appeals to not just the weird pansexual furries but more "generic" stuff like Reinhardt or McCree(although that one got hit with the name change and all that but still). Even female chars have like Dva and Mercy which don't have really any sexual orientation or racial diversity quirks(I mean Dva is korean I guess but that's hardly the same ballpark).
Concord character just look like shit, really poor design. Similar color palettes on a lot of them, few clear defining character traits, slap on very shitty ingame customization(Overwatch had a bunch of skins right away, a lot of them with pretty different designs from the original) and yeah. And then obviously the game itself wasn't particularly good from what I read, so it's not redeemed by that.