That's probably the biggest factor most Pro-SDF/Anti-7 see
It's "Too spaced out" to be believeable
Macross wasn't about "Magic" it was about science
it sometimes seems like M7 is a fantasy (I can picture Basara attacking his enemy with sword, shield and singing out loud)
and in 7 the magic was laid on thick! (this is something I hope they avoid in M0)
In SDF-tv it was just a normal singer, it could have been anyone (it could have been a pron-movie as Duke pointed out)
in 7 you had to be special, not talented but special with powers beyond belief
maybe that's a little overrated statement, but it sure looks that way
And this is where I think the Anti-7 crowd is incorrect.
M7 wasn't really about magic - Basara didn't have special powers. He could have been replaced by anyone with strong enough conviction of will. This is why Mylene also had the power at the end, but had to struggle to grow for it. Ray and Vefidas also had the power. Noone ever accuses them of being magic. Gigil also grew into the power (as well as the other Protodevelin).
Anyway, to me this isn't magic at all. It's a scientific principle - measurable by science and even able to be harnessed and enhanced (sound boosters, big ass sound gun at the end).
As for Minmay, didn't Chiba actually dub this the Minmay effect, or am i getting things mixed up? It's been a bit since I saw it last.
I disagree with the pron film assertation. But I do think that it didn't have to be Minmay specifically - it could have been anyones else that happened to have the heart and conviction that her singing could stop the war.