Popa,
I suspect that YCT will say that they are also getting their values from Chazal, but that those values are in conflict with some minhagim we have because of changes in the society around us.
So to go back to women’s aliyos, let’s assume their interpretations of “kavod hatzibur” are correct (and I am not sure it is) that the lack of kavod was because it was considered inappropriate for a women to be an a “men’s section” or because it was insulting to men that they “needed” a women to read the Torah for them. On the other hand, because of the mores at the time, women would not be insulted by such a minhag.
Chazal may have been ambivalent to whether or not men should be offended about this. But they held that if men are so offended then women should not get aliyos because Kriyas HaTorah should not be a source of strife and b’zayon. (I realize that this is rank speculation, this is just a hypothetical).
If the main point is that Kriyas HaTorah should not be a source of b’zayon, then today, where men will not find this inappropriate and where a baal koreh reads everything anyway and where it is women who are embarrassed, offended and insulted by not getting aliyos, then the kavod hatzibbur falls away or would mandate that women should get aliyos.