I could make a list of Orch. who ONLY recorded dance music for the ballroom world, and did so for over 30/40 yrs... even today, orch like Tony Evans,have sustained an ongoing career devoted to the genre( there are several others in Europe ).

In addition,the teaching side of the profession would suffer greatly, without the constant output of " danceable" music for lessons.( I have invested several thousands of $/ for that very purpose, as do most teachers, and continue to do so )

As to what profs do in exhibitions.. they are just that.. exhibitions. Never intended to infer that the songs or the tempi they use, are indicative of what should be used by the general dance public.

Context is the key word in ALL show type dances ; most are created to demonstrate skill.

Also to consider.... what the average band plays at a "public" dance. should not be compared with the world of strict tempi.. when I DJ for my socials,( Ballroom and Salsa ) the program is varied to suit the not so proficient, and also casual, attendee, as well as the "trained " dancer .

To give a further e.g. and extrapolate the tempo " theory " for the newcomer to the dance world..many yrs ago, 1 ex world champ. would Demo. a V.W. and another a Charleston..
again,showing "dance "proficiency .

Point is... we should not "read " too much into the performers interpretations. and take them for what they are..Entertainment..