We should reject hard-to-drive speakers more often

Measurements from a reputable source always help. Most makers do not overdo the specifications for fear of either confusing people or scaring them off. It’s just the way it is.

Again it’s a different ballgame these days for those willing to use Class D amps. Freedom of choice rules. That and reliable measurements. The more the merrier. I’ve read of some supposedly easy to drive speakers that turned out not to be. A good rule is the smaller and more bass extended the less easy they are likely to be. Fritz speakers are the ones I know of that go to great extremes to provide an easy load but they are not very “efficient”.

If you buy stuff that doesn’t work well together, guess who’s fault it is ?

+1 @bdp24. It’s all about the bass. The bass! Not the treble.

Driving speakers effectively that is.

You need an amp and speakers to make sound.   As long as the amp is up to the task you are good to go.   Granted many may not realize that their amp is not up to the task. 

It’s not a problem practically in most cases anymore with modern efficient Class D amps. Having choices is a good thing. Most people want their hifis as a whole smaller and less obtrusive these days (if they even want them still at all). Smaller harder to drive speakers with practical more efficient amps needed to drive them solves that problem.  To each their own.