I think there are a number of factors at work in all this.
First, the U.S. culture shift. I'd guess the majority of men I know to wear fragrance either bought it to go out on a date, was given the scent by a girlfriend or possibly a relative for Christmas, or are metrosexual (or at least comfortable enough to walk into the "Beauty" department of a major department store, and even ask for help.)
There is a real apprehension among a lot of younger guys that feel their masculinity challenged when visiting the fragrance counter and asking to sample a scent. "Guys just don't do that," especially if they are shopping in a group say female sales associates I've asked in the past, unless they are angling for a date with the SA. Girls will without a second thought.
Now at the risk of stereotyping, and I don't mean to do that, I have noticed this apprehension does not exist with Latin American guys, who I've watched scour the fragrance sections at department stores and discounters. They are often informed about different basic scent groups, although not necessarily certain of what individual fragrances fit into which group. So I've heard conversations about choosing scents based on phrases like "that's a clean one," or "you'll get noticed wearing that," or "this would be good to wear at church/party/event." Plus they know that Beverly Hills Polo Club scents at TJMaxx are "trash."
Older men will often shop confidently, although many that don't know any better end up spraying a litany of testers on themselves resulting in a fragrance cacophony. One SA who worked for a regional department store told me stories about one strange man who insisted on spraying testers into his mouth. He was a legend and many fragrance counters experienced his "testing" until he suddenly disappeared.
Notice how marketers have adapted to the culture shift. "Axe will get you laid" is the basic premise of this scent in North America. Adidas makes you feel sporty and active.
European houses will put airbrushed hairless male models wearing next to nothing lying all over the place to sell to men. Americans will put the youth-targeted scents with an average teen or 20-something geek next to a babe and suggest with one spray, you can do anything you want with her. It's far more direct: A will get B if they use C. I'm sure most Europeans don't think if they spray Le Male, they will suddenly transform into a ripped male model in a sailor suit.
Notice the expanding line from Old Spice with names that conjure up dark folklore, creatures of the night, and fantasy icons. It's not your dad's scent anymore. The marketers are selling the imagery as much, if not more than the scent.
The celebutard fragrance lines are another example of how marketers are getting around the disinterest most Americans have in fragrances by marketing the celebrity, not the scent. Unless it smells intolerably bad, the celebrity endorsement is what pulls the buyer towards the product. If one associates with or likes that celebrity, the shopper might assume if the celebrity endorsed it and wears it, they can show their support by wearing it too. Marketers know this because the dirty little secret they don't dare to mention is that scents associated with African-American celebrities sell much higher among African-Americans than, say, something from David Beckham or Paris Hilton. Notice the scent itself barely matters. Most general retailers don't have room for testers anyway or they disappear, so a ton of sales are blind buys.
So this is why there is a big disconnect. The mainstream fragrances these days are celebrity-endorsed or value-priced items with names like Nautica. Slightly more upscale mall stores mass-market scents that are safe sells, hence Acqua di Gio. Niche is not going to turn up a whole lot at Macy's and most guys cringe walking into Sephora or a Guerlain store. Even Yankee Candle is threatening to a lot of guys.
Once you are willing to commit more than $100 on a bottle of fragrance, you are either filthy rich and don't care about money or you are a real devotee. There are fragrance houses committed to selling to both. Based on the various threads here, the one that comes to mind the most for succeeding in that department is Creed, which has its vocal critics and fans.