so many speakers

For a moment I thought you asked WHY are there so many speakers on the market. That would have been one of the best questions ever, and I was prepared to bet all my Tiny Tim LPs that no one would get the right answer. Close but no cigar!
Cheers

"but if your speakers are discriminating against drummers they are making arbitrary decisions and need a stern talking to."

They are also in violation of the 1964 civil rights act which bans discrimination against signals based on it's frequency.

"If the answer (or consensus) is "NO," then how can one in the market for new speakers make an intelligent and informed decision?"

There is NO CONSENSUS concerning ANYTHING on this site. Ask ANY question about ANYTHING and you will see. You cannot use the posts / answers on this site as factual evidence about anything!! It's a big waste of time to try. Find speakers you might like based on size, cost, looks and specs and listen to them. If you like them, case closed, Phase angle and crossovers and impedence notwithstanding. Can you hear phase angle? We as a species can barely hear a full grown male lion coming thru the grass. All of our senses suck! Get what you like and be done. For every person that says buy A, there will be just as many saying buy B, and a few saying buy Z.
And nothing you asked has anything to do with technical expertise. If all 'opinion'. And trust me, EVERYONE here has one of those.
Cheers.

"Surely there's a consensus that there are audible differences among speakers!"

Yes, there can be differences. But, I think there are fewer differences than we might think. If we could really test them, we would find that there are 'groups' of speakers that are sonically the same. In other words, my Polks could end up in the same group as the Wilson Maxx. :)

So, of ALL the speakers on the market, we could end up with just a few different groups. Some people think, believe it or not, that speakers are the ONLY component that exhibit differences. :)
Cheers.

"Wrong! And on so many levels"

See! We can't even get agreement on the fact that my Polks are the equal of the Wilson Maxx. If we can't get agreement on something this obvious, what chance is there of coming to agreement on more contentious questions! This gentleman made my point.
Cheers