I think a social critique of romance consisting of primarily/uniquely of sex appeal would be valid. However the album itself seems to promote this, to a certain extent "I could never take a chance, of losing love to find romance" can definately contain emotional/intellectual attraction present in a fling but when it is put in direct contrast to "love" one thinks at the very least of increased shallowness, and nothing says lack of depth like physical superficiality. I suppose you're going along the lines of Love contains elements of Romance, and though one has precedence over the other they aren't mutually exclusive?
If the shirt is meant as a refute of classical puritanish ideals (perhaps along the lines of big girls are best) ie my wife is a mother and I love her but I find her sexy and there is nothing wrong with that, that'd be cool with me - and it seems to be where you were taking it. But the design of the shirt seems a bit off for that... and it would make more sense for "Beauty is good" or something from the band. And again the shirt didn't say "Romance is good" but "Sexy is good" so your last remark doesn't really apply to the shirt in and of itself.
