Hi-hat lighting fixtures should never be allowed to come in contact with fiberglass (or any other type) insulation because it is quite simply a fire hazard. Does the electrician who installs them not care? Does he not know any better? Was it done by a homeowner who is clueless?
Probably a combination of all of these. But it really is hard to believe how often I see this in the attic. I would have to say about 75% of the time, and that is a conservative estimate.
Now, many people will say that it doesn't result in a fire very often. Yes, this is quite true. But wouldn't it suck if your house was the one out of (who knows how many) that actually burned down as a result of this "totally preventable" mistake? I know I would be pretty upset if it was my house!
And some of you may also say there is such a thing as a zero clearance hi-hat fixture. These can be installed in contact with the insulation. I say no! Why take the chance? What if somebody puts in a light bulb of the wrong type, or one with a very high wattage which causes overheating.
I suggest that every home inspector who does not look for this, and/or does not include it in his report, is doing his client a real dis-service. He also may be opening himself up to a big lawsuit.
So, let's be careful out there!