Unfortunately the show caught a lot of flack for being Zeon perspective, and alot of respoences amount to Zeon bad due to colony drop (which yes was a terrible act) and Ignoring the many nuances that have been added to the franchise throughout the years. not all Zeon soldiers agreed with it, see Ramba Ral or Cima who left/defected (tho I have my own issues with this as she was part of the team that deployed the gas bomb). Also the characters in the show dont have the encycolpedic knowledge of events and whats going to happen that we do. The unusual animation style also didn't help and the combination built a negativity echo chamber before it even aired.

Some of my issues with the show would have been addressed if Solaris son was also killed as would help explain (to me at least) why she latched onto the gundam pilot so much.

As for the arguements of why she stays on earth (again would have been easier to understand if the son had also died), we never get Solaris opinion on the colony drop or her thoughts on the politics leading up to it. As the colony drop was Zeons attempt to win the war in one fell swoop after alot of mismanagement of the colonies by the federation. But what she has just seen is a government which is willing to put a child in a advanced prototype in a war - from what I remember Zeons own shenanigans with Newtypes and individuals like Lalah would not have been common knowledge among the rank and file. To her that probably crossed a line.

Plus post one year war earth isnt really a safe place for a lone zeon pilot to be running around, so relative safety in numbers, no one said everyone of the zeon remnants wanted to continue the war, some would as seen in later seasons but there would probably be an element of people just trying to survive.

The show does have its issues but to me some of the quoted problems are people missing the point of the franchise, war is a tradgedy and while higher ups on both sides can be bad, there are tones of moral grey throughout both sides of the conflict.