>>Bottom line: is phylogeny the pursuit of groups defined by relatedness or perceived similarity?

Phylogeny is absolutely the pursuit of groups defined by relatedness (i.e. monophyly, not paraphyly or polyphyly).

Phenetics (a dead science) is based on similarity with no regard for relatedness.

Frankly this is a silly debate. If you want to understand this stuff, read the literature. I entered this discussion to direction some to that literature, not debate an issue that is essentially dead.

Cheers folks!