All the comments can be roughly divided into the following schools of thought:
- if you take care of your appearance (which seems to imply a suit and tie, but really, why should it?), then you'll take care in other areas of your life: hopefully your job is one of them.
- if you don't care about how you look, that's because all your passion is used in other areas, hopefully including whatever your job is.
- if you take care of your appearance, the you're an empty talentless preening dandy. Middle management beckons.
- if you don't care about how you look, then you're lazy in everything. You'll be crap at what you do because you're a lazy slob.
Generally I think all of the above is true, but for different people. The biggest skill in interviewing is working out what (if anything) drives someone and hiring accordingly.