@john1 Most music doesn't reach frequency extremes. There are notable exceptions like orchestral music. Now, objectivists will pretend to exclusively listen to orchestral music in an attempt to make fullrange drivers look awful (unintentionally). You can't fault them for seeking the most versatile system in absolute terms.
However, if you're looking at speakers below $2k (arbitrary number) you'll see that many models have poorly matched woofers and tweeters with badly designed crossovers. But they measure really well on a frequency response graph! They have sufficient bass and treble on top. Everything seems fine. But subjectively I find the midband/vocals veiled and the bass is slower (it's not a dealbreaker).
Now I'm not gonna pretend to be the most knowledgable person in the room. It's quite the opposite. Anybody who evokes fullrange drivers in a positive light is a dunce in the objectivist crowd.
The experiment of listening to mutliple 'affordable' speakers in a showroom (fullrange drivers VS 2 way crossover) is informative. I value vocals, acoustic guitars and bass guitars highly because I listen to mostly indie/folk/alternative music. So fullrange drivers were my choice. But if you listen to prog metal and orchestral music you'll probably prefer multiple drivers with a crossover. Either solution sounds great. I am not picking winners here.
I evoked the issue of price. Amazing speakers which command a high price should have well designed crossovers with properly matched drivers. So they should exhibit the same positive characteristics we expect in fullrange drivers.