Like obfuscation, golf is an art. Most excellent golf entries are the result of evolution, experimentation, and creativity - the solution is not approached the same way one would approach a practical programming problem. Fewest characters is actually a sensible criteria as it adds a fun twist that skews the rules sufficiently to ensure that the game is not boring. Experienced programmers no longer have an untouchable edge when it comes to golf.
If another scoring mechanism was used, my personal preference would be - fewest nodes in the compiled op tree. Of course, this breaks down when eval"" is used, but the idea still stands - the eval"" case is just hard to calculate.