These ass-backwards priorities would work on a character that's a 13-year-old kid in our time, but since these are mature adults who live in the enlightened 24th century where hopefully Looks (and perceived amounts of testosterone) Aren't Everything, I'm going to go ahead and say the question isn't what's ludicrously stupid here.
Rubbish, pure sexual attraction is a major theme of Star Trek in the 23rd and 24th centuries. Biology won't change in 2 or 3 hundred years. 7 is much more physically attractive than Janeway so unless 7 has some major and I mean major character flaws then it is beyond ludicrous to think that Chakotay would actually even consider the sour faced hag Janeway over 7.
Recognizing prejudice is also a major theme in Trek.
Kes loved Neelix, Dax loved Worf, Leeta loves Rom.
Trek has shown several times that beauty is in the eye of the beholder and a doesn't determine relationships.
Especially in this day a age, woman Janeway's age are considered the new 30.
Seriously?? What is this, a POPEYE cartoon?