Sorry, but no, you are wrong on most things you write below this. Styrofoam is a building material, one of which function is isolating. That is it. Building material is not decoration. Decoration is using something just because of its visual effect. As I said, that is also not that common in old buildings. Most of the old buildings were smart.
Flat roof could be smart. Because they take much less volume than classic one. Building that is 20 meters wide will have 8-10 meters high roof. That space is harder to use and you will have much more shadow on neighboring plots. Pitched roof that has unused space beneath it, provide isolation and another level of moisture protection. If you have apartment there, you have exactly the same problems as with flat roof. It all depends how good things are done. So, flat roof could be good or could be bad, but you cannot say that it is bad by itself.
This is again such a broad generalization that I will reply: 'Yes you are partly right, but on a whole you are completely wrong'
Yes you believe that, because you accepted many things that you hear are true. Usually it is just a pile of hearsay. like the things about roof and Styrofoam. I don't think you are stupid (as you said that we architects think), but it is because you don't try to understand things, you don't inform yourself about it and you don't think about them.
This is also completely utterly wrong, read some essays on art at least. Btw, architecture is not art.
My opinion is that, it is wrong to label things and generalize. Are cheap houses ugly? Yes most of them are, especially when they are done by lazy architect. But it doesn't matter if they have flat or pitched roof. Also faking is wrong, but actually we will always found traces of it everywhere. Again it doesn't matter if faking is square or circular.
Architecture is solving technical problems inside the frame of investor's wishes, economical soundness, solving social problems and finally to satisfy personal esthetic views. So actually we can never be satisfied with our work, but we can also easily dismiss too - simplified arguments.