They specialized in convenience-product markets, they know how to make a deal with Wal Mart and the sorts, they can handle a mass market brand like Old Spice, but when it comes to the specialty product market they lack competitive advantages.
For instance, observe how they are missmanaging traditional high-end brands like Rochas, and when I say "missmanaging", I mean minimal presence in key markets and / or either licensing the brands without much coherence as the original brand proposal - you can get Rochas clothes in here, it was licensed to a local manufacturer which sells Banana Republic-style men's clothes in the mid - upper local price point.
So chances are they are bargaining with high end department stores in the same fashion they do with Wal Mart: they just can't, it is not what they are used to, plus learning is highly cost demanding (time and money) - you know managers are not patient people.
As to competitive advantages, they are champions when it comes to cost: low production costs, high rotation thanks to deals with big supermarket chains and massive distribution, meaning huge profits in a market that is quite inelastic: it takes a war for people to stop taking a bath. It takes an economic crisis or the perception of one to come for people to stop indulging in affordable-and-not-so-affordable luxuries.
What about niche competitive advantage? Ask the owners of Amouage, Hermes, and if you want to ask yourself how, Monsieur Arnault (who happened to be a business wizzard, for he achieved a real a contradiction in terms - he is the one behind much of luxury's luster fading out, niche brands that are massively distributed on a global scale, take that). Sure, breaking a deal with Barney's is a complete different story, there are several Ms. Wintours and Vogue-like magazines in between, for instance.
So I think P&G buys these prestigious brands, let them sleep with the idea in mind selling them after some key strategic movements, like launching a long cherished EdT sold at a hefty price just to discontinue it or restricting its distribution to a flagship in order to keep the brand alive at minimum costs. After all, they want the brand to increase its equity in order to sell it to LVMH or PPR or any new luxury-market company for a hefty price.
BTW, Unilever tried with a prestige line of cosmetics, they gave up. Axe is a total hit, why the need of complicating things with Calvin?
Think of this as a businessman, it is not a bad idea.
Signed, Pollux, the greedy Base Noter.