Yes, I agree with what Overread (and a.u.) said.
If you look around, practically every DSLR that has come out in the last 3-4 years, has plenty of people saying that they aren't happy with it. As mentioned, this is mostly due to their expectations of what Canon/Nikon etc. was going to do with the new model. Everyone wants a professional level camera that shoots at 50 frames per second and can go up to ISO 1,000,000 without any noise etc. :roll:
The 60D took a turn from the path created by the 20D, 30D, 40D, 50D. The 60D is more like a Rebel, than the 50D was. Thus, many people were disappointed with it.
I don't know how many of them actually bought the camera though...they just complain about it on the internet. :er:
Also to consider, is that the 7D is the next model up, and not all that much more expensive. So I could see that people would buy the 60D, and then wish that they had paid a little more for the better model. That's not a camera thing though...that applies to cars, houses, stereos, dishwashers etc.
I see plenty of 60Ds in my classes. From what I can tell, it's a nice camera...certainly a nice step up from the Rebels. In terms of image quality, I'd think it's on par with the Rebel T21 & T3i....it's the body and features that move it above them.
I also see a lot of D5100 and D7000 cameras. I don't know how they compare price wise, but in terms of features, I'd probably choose the D7000 over the 60D. The D7000 is more like the Canon 7D. Although, I don't think the D7000 has an articulating screen (I know the 7D doesn't). So if that's something you want, the 60D has that advantage.
To be fair, I haven't compared the image quality of these cameras.