IMO, the two aren't really comparable. GRASP is basically a philosophy of design. Patterns are concrete examples. Some (many) patterns embody the GRASP philosophy -- but others don't.
At least IMO, a lot of the appeal of patterns can be traced back to differences in basic mentality of hackers vs. packers. Simply put, GRASP, as a philosophy of design fairly explicitly embraces the hacker (mapping) mindset. To apply it, you need to do mapping -- understand the problem, and it provides philosophical guidelines for imagining and designing a solution.
Although they weren't intended that way, patterns have been (mis?)interpreted by many as a way of making programming fit the "packer" mindset -- memorize this set of vocabulary words and be able to quote their definitions from the GoF, and you too can be a real
packerprogrammer. It also fits well with much of the (packer dominated) corporate mentality -- packer PHBs and give their packer HR people a nice, neat list of "patterns" that the prospective candidate needs to "know" before they can be considered for job X (a typo in quoting the definition of "dependency injection" is a clear sign of incompetence, isn't it?)