If you understand the MTM layout you know it'll always be bad, even without measurements, so there is that much. But I agree that isn't common knowledge at all.
Your setup looks fine to me given your constraints. This is one of the reasons I hate these center channel threads. It frequently comes down to people who bought them saying, basically, "it's unfair to say my speaker choice sucks because I didn't have a choice due to budget/physical constraints/whatever." Not every system needs to have the best possible thing. If it outputs sound, and you're happy with it, that's fine!
It's a different thing to pretend that, because you were stuck buying one, that means 2-way MTMs are as good as other options. Everybody who understands the importance of smooth off-axis response knows they're not good. But sometimes you compromise. My 4" PC desktop speakers aren't great, I have no illusions about that, but that's fine. I just expect them to output sound and not take up space -- not to compete with my Genelecs.
The purpose of this forum is to find the best options for sound quality, but sometimes other factors have to take priority. That's just life. Nobody is(or should be) judging anyone because of what products they bought. Unless it's $10,000 power cables. Then you're a dumbass.