Careful – here comes an opinion. Personally I think the goggles and potty combo looks hilarious. If and when the need for it arises my mates and I frequently laugh at each other.
However, sometimes ones riding cant simply be categorised into just xc/or downhill or any other neat little box. When I’m not riding proper DH courses I normally wear my pot. It’s my only other helmet. I like the protection it provides, it’s cheap to replace and I’m not overly worried about ventialtion 11 months of the year.
Occaisionally one might engage in some very long very fast, descents where wind, insects, roost and all manner of flying crap and be a hazzard. Hence the goggles.
What about glasses I hear you say? Well, I had a pair, I fell off and they broke. They were very expensive and supposedly very very resiliant. In practice they were not, they didnt even stop the wind getting in my eyes on many occaisions. So Im not wasting any more money on them. Goggles are cheaper, more robust and completely stop your eyes from streaming when the going gets very very fast and the shit starts to fly. Glasses dont.
Goggles are no more difficult to clean, the lenses are cheap to replace, they protect more of your face and if they break who cares. Take them off on the climbs.