PH and sour / acid taste
There's a bit of trickery going on in the comparison of vinegar (acetic acid) to spirits of salt (hydrochloric acid). Your 5% (0.83 molar) vinegar has a pH of about 2.5.
You need much less of the stronger acid, HCl, to reach that same pH (2.5); in fact only 0.003 molar, a factor of 277 less.
Since you taste the anion (acetate or chloride), not the proton (H+), it's no wonder that the vinegar is much more flavorful; there's a 277 fold difference in the concentration of the flavor agent. Pick a different acid, and you'll get a different tasting anion, and a different concentration needed to reach pH 2.5.



Response to comment on taste of anions:

Your linked Wikipedia article gives the impression that the taste reception system is fairly simple, and well understood. It is neither.

Here are a couple examples of reasonably current research on the taste of anions:

The Anion Paradox in Sodium Taste Reception

Anion size of sodium salts and simple taste reaction times.

Take a look at Wikipedia's article on taste receptors. you'll see that 'bitter' tastes are subclassified by 30 or more different receptors.
Salty taste receptors (specific anion and cation) are still are poorly characterized

Research on humans is hard, so it'll probably be decades before the mechanisms of tasting are fully sorted out. Until then, consider sources like Wikipedia expositions of the current state of knowledge, rather than the final word.