Because they're cheap, and they are popular among spammers and MFA webmaster, so bad reputation, IMO.
An .info is not the same as a .com. Type in's are less likely, and more people know about a .com or a .co.uk than an info. Plus, .info's are dirt cheap. You can easily get them a for a buck or two. While there are good sites with the info extension you will come across plenty of spammy sites. Over a period of time, your valuation of that extension comes down.
.infos sell for a low price because most of the sellers sell it within the first year itself. So the buyer knows that the seller has got it for $.99 or $1.99. However the ones which have aged go for a good price as can be seen @ sedo and other domain aftermarkets. ARonald
You're right about the bad rep. They gave out 50 free ones for a year not long ago at Registrars and I had 400 myself. Most were being used for Spyware, Trojans ect that it's hard to get them listed in some places..
Here in Portugal AMEN hosting use to offer to they're customers .info domains at 0$ 1st year with 1GB Hosting :O And yes, I think that kind of domains have a bad reputation. BUT if a client want to buy a .info domain, I certainly will sell it )
When was the last time you did a search at Google and found a .info in the top results? I rest my case...
There are some out there like rail transport companies, but it's really more suited for informational sites because of the extention