It's definitely the fastest way to increase one's income, and you can't blame people for doing that. My first job was doing technical support (first full, then part-time) at $8.50/hr, and the subsequent 5 job changes were simply progressions to a very modest mid-level IT salary in the $50-$70k range. I don't think that's ridiculous.
As a hiring manager, I would not hire someone who has been job hopping for the same position. Think of it as a twist on the Peter Principle.
My jobs were all in different subspecialisations of technology, but there is a certain identifiable sameness that unites all of them, and especially unites the first three (ISP and SMB-oriented IT consulting work) with the last three (VoIP & TDM telecommunications).