The surge of interest in single-malt scotch is easy to understand: they are quirkier and more intense than traditional blended scotch, and the range of style is far more broad than most blendeds. Single-barrel cask-strength scotches are even more intense and interesting than other single-malts, but there is far less consistency.
That said, there’s something to be said for the blended: they are far less one-note than many single-malts (my friend Stu is wont to complain about the single-flavor problem with single-malts), and uniformity is far more achievable than single-cask scotches.
Why don’t people blend scotches at home? A couple of particularly delicious single-malts (Lagavulin 16-year, Highland Park 18-year, Balvenie Portwood 21-year, Talisker 10, Bowmore Darkest, Springbank 10, and Glenlivet 12, for example) can be mixed together to achieve interesting and sometimes quite tasty results. (I’ve conducted a little bit of experimentation to verify this.)
One could mix by the glass, in a graduated cylinder of some sort so as to be able to record proportions for note-taking and accurate reproduction. This might also be a market for drink-mixing robots, so as to guarantee the consistency of the house blend. (Like homebrewers, perhaps some home-blenders will print up their own labels and give them to friends to commemorate special occasions.)
It would be an expensive hobby, sure, but hardly on par with owning a yacht.