One reason why it sucks as background is, you generally don't find purple as background color in a natural setting. White (snow), blue (water), green (landscape

One reason why it sucks as background is, you generally don't find purple as background color in a natural setting. White (snow), blue (water), green (landscape), grey (clouds) - are all good choices for background because they are associated with natural settings. A strong color such as purple distracts the attention from the foreground, defeating the purpose of the background.