Women have a mind of their own which are extremely irrational in some circumstances.. especially when dealing with clothing, house ware, design, relationships, etc. They just don't see the same things a man sees. For most men, especially on this forum, sound quality trumps aesthetics.. yet a woman would give more priority to aesthetics (like in this case) over sound quality. Woman like "cute" things rather than "macho" things. If the Bose is pleasing to her eyes, then it is likely pleasing to her ears too. I don't want to generalize too much about women, but this seems to be the case here.
Anyways, you could try to educate her about sound quality differences, but that won't get you far. She might find that you don't appreciate what SHE values, and think in terms of what YOU value. I agree with a previous statement that this isn't a fight you can win. You might try to compromise her position a little by not getting a Bose, but get something that you think she will find cute. I don't have any recommendations, but look for something small like the Bose and have lots of curves and simple to use. Gently discuss these Bose alternatives with her and see that she has lots of other options. That's the best you can really do in this situation.