From a series of forum posts:

Person 1: I wasn't all that impressed with [Johnny Walker] Blue... it seemed to go so far down the "how smooth can we make it" path that it didn't have a whole ton of personality... Person 2: People don't drink Johnny Walker Blue because they like it... people drink it because they can then brag about it. It's like lighting a cigar with a $50. It sure doesn't make the cigar any better. Person 3: Law of diminishing returns. The first few dollars it's easy to tell the difference, after a while it becomes nigh on impossible.