I do get a little frustrated when that happens for both Banners and Landscape....
I use textless Posters for my main movie section (itself a challenge when the only sources you can find are texted versions (!) - thank goodness members here have given me tools to clean them up), but know that Banners are popular, so I just think of them as different shaped posters.
I try to work to the view that every layout should look as amazing on screen as I feel my Posters view does.
I even do two versions of EVERY fanart I have - one that works for the RIGHT view I use (so everything shifted over, so not hidden by the poster - that can sometimes take a lot of manipulation of the source) and one for the site
For me the image isn't just about itself but also how it comes together with all the other images and overall layout people might chose in their set up view. Giving just one example, I really appreciate it when people find unique images for the cdart, so its different alongside my posters
