Depends how you look at it. In general, yes. Fashion is largely aimed towards women, due to both their collective interest in it, and probably to most men being more drawn to looks than women. Women seem to be very competitive with each other in that department too, as evidenced by the old adage of "women don't get dressed up for men, they get dressed up for other women." Meanwhile, us guys who DO put a little effort in, I could give a fuck less what other dudes think of it, haha. Obviously these are sweeping generalizations, but that's all you can operate on with men vs women issues. I think it just kind of has to go without saying that certain individuals will obviously deviate from these concepts.
But I'm a guy who medium-cares about fashion. I wouldn't say I'm a fashionista by any stretch, but looking good is very important to me, I like to wear relatively nice clothes, and above all else, I like to look matched and well put together. I'd say I'm more into it than your average guy, but I'm not above shorts or jeans with a t-shirt. They just have to be relatively nice articles of clothing that work well together and suits my coloring. Like I won't be caught dead in Walmart Velcro cargo shorts with 18 little mini-pockets on each leg and the promotional Southern Comfort t-shirt the shot girl gave me at the bar, haha. But it's not like I only wear tailored Armani suits or wear all those fruity looking outfits that fashion magazines will tell you look good. But no one will ever say I look like a slob.
But to directly answer the question, yes, I think women are more understanding and accepting when it comes to guys. I've known guys that had hot girlfriends that just wore their Under Armour gym clothes all the time, haha, but they were attractive dudes and obviously got along well enough with the girl for her to overlook it. But at the same time, I don't think guys hold women to that standard either... kind of. Attractiveness is very important to us, but I also feel like a lot of guys aren't analyzing it that hard. We just see a girl and we think "hot" or "not." It's not usually like "she's cute, but what is she doing wearing THOSE shoes with THAT top?" It's just little one or two word phrases going off in our mind. "Whoa, cleavage...", "Bare midriff...", "Nice butt..." hahaha. It's all pretty simple. We see something and identify it as hot, but might not be able to explain why, it's more of a sensation than a conscious thought.