Two friends of mine are single malt Scotch
connoisseurs/mavens/fanatics. They go to Scotland every year to tour
yet another distillery. One is committed to visiting every last one of
them before he croaks. Whence cometh this fervor over single malt
Scotches, and do Scotch experts believe they are in some sense
"better" than Scotch blends?

When I was at the liquor store today, stocking up for four house
guests (three old high school classmates in their mid 60s, one of whom
is of the pair that goes to Scotland), I noticed single malts from $30
to $315, the latter a 25 year-old Glenmorangie. A few feet away was a
bottle of Johnnie Walker Blue at $200.

I realize, of course, that taste in Scotch, like taste in anything, is
purely subjective. But I'm interested in knowing whether reputed
Scotch connoisseurs find anything more desirable in these single malts
than in blends and, if so, why. (After the first or second glass of
the stuff, I shouldn't think the difference would be detectable!)