It's surprising to me that Sephora still hasn't arrived here in the UK, although I've had the pleasure when visiting New York, Rome, Washington, and Prague. This is because I generally can't resist dropping in when I see a shop with lots of perfume. But I've always found them to be quite boring and same-y, and when I've lived in places with Sephoras I rarely visited once the novelty wore off.
Plus, like you say there are those hot lights, so I wouldn't buy something there that I could buy elsewhere. And I can definitely buy elsewhere; I'm lucky enough to have Liberty, Harrod's, Selfridges, Les Senteurs, and myriad little boutiques nearby. Also, larger stores in the Boots chain have a very similar selection to Sephora's.
It's a real shame if Sephora threatens smaller perfume shops. I would hope it wouldn't be too much of a threat to tiny niche perfumeries, though, because it doesn't have the same stock.
And perhaps it does provide a convenient place for new perfumistas to test and try, but I wonder how many Sephoras are in places that don't already have a pretty good selection. Like I said, I've only seen them in major cities, so my experience is limited.
All in all, I don't care for Sephora because I'm generally opposed to the consolidation and the "Wal-martization" of everything, which seems to be trying to turn us all into clones that look and smell alike and eat all the same food, yada yada.
Also, I think your title was good!