There is a very strong bandwagon heading in the direction of the (Sloan Digital Sky Survey)
ugriz system, in the literature. However, this is still a very broadband system with limited resolution. In fact, ugriz it is
not that much different from UBVRI , except that it has a broader wavelength coverage.
(see:
http://www.sdss2.org/dr5/algorithms/...Transform.html
Galaxies papers are now very often on the ugriz system.
Perhaps the Johnson-Cousins UBVRI system has been maintained for convenience and for the easy ability to to intercompare new stellar data with the older photoelectric photometer observations that were the basis of our study of stars.
We do carry a lot of historical baggage in astronomy; many have said that the magnitude system would never have been kept on, if astronomers were rational people;
indeed, mid-infrared and submillimeter and radio astronomers have never adopted it.