Some people catalog information every day, so it matters to them for practical reasons. Same with people who rely on those resources being accurately cataloged.

I'm ok with obsessing about the data.

Presentation, an order of magnitude less.

Substance >>> style.

You're missing the point. Citation formats are not a matter of style here. It's about making research results easier to find, which directly affects the quality of new research.

Cataloging format is to style as database modeling is to... well, style. It's got nothing to do with aesthetics, it's about describing the data in a way that makes it useful later.

Have you noticed that search engines suck?

Citation formats are an attempt to end up with a search engine that doesn't suck. (They can do lots of other things along the way.)

Options:

1. Accept any format and try to turn it into your own internal representation. Problems: (a) your own representation is a citation format; (b) you need to write an infinite number of converters and hire an infinite number of trained people to work out the edge cases.

2. Accept a limited number of common formats. Problem: your search engine will not be useful for a majority of the corpus.

3. Convince everyone that your new citation format is unstoppable. Problems: (a) convincing everyone; (b) actually having that citation format cover, say, 99% of the cases; (c) XKCD#927 (Standards).

Dublin Core is/was a terrible attempt at a type 3 solution.