I agree with your disagreement.

Seriously. I do agree w/you. I think we hear the "doesn't matter" line as backlash against the overuse of standover as the one-and-only measurement. I like to look at top-tube as first number, and then secondarily at standover.

To the OP: 17.5" is probably the most common frame size out there. It should be easy enough to find that size frame to try out.

You might even prefer a 26er, but that is a heretical statement that I will disavow having made.