Even if they did that, they couldn't not make her a mother of Unn-Unn. Plus, I don't think the Artists would make new art for her to make her more "western friendly"
Have you seen Brady's Confession? He may not be Azure Jerome or Chambrey, but I still think he's pretty good looking (not that transfers to usefulness, but hey)
Because Henry is Henry. Also, I think most of us plan on using every character (I do at least) regardless for supports, also, like FE8, you can actually make use of low level characters who join later.
For some, it's simply shipping. The fates that befell otherwise nice wonderful girls like Rinoa and Kairi.
I like her though, but I usually like Flyers, even I do only use one Peg and a Dracoknight.