A designer being upset about a negative review is understandable. After all, they work hard and long to maintain their status in the fashion spectrum, and in such a competitive field, reading a bad review is probably frightening to some designers: what if this review has a strong impact on consumers? What if this is "the" review that is remembered? As quickly as some designers have risen to the top, they can fall just as quickly.
On the other hand, banning reporters kind of sends out a message that the designer is doubting themselves (at least, that is how I see it). I mean, if Mr. Armani was very content with his collections, than one review shouldn't be too harmful for him. However, banning her for an unfavorable review seems to suggest that Mr. Armani is not too pleased with how things have been going. Only allowing people who praise you into a show contradicts the fashion industry itself, doesn't it? Fashion is a competition and it's about the highs and lows and the fight for the top. If one is just letting their biggest fans into the show, then what is the excitement? Really, the public is not getting a true view on how you're doing, and there is nothing to encourage you to push further.
Maybe instead of taking the easy way out, couldn't Armani push a little further with their collections? Not always an easy thing to do, but being completely stubborn about the subject is a turn off. Keep Armani in Armani, but add something new, yes? Isn't that what fashion is all about?