If you want to make a living as a novelist, write genre.
True. You'll have to be very lucky to make a living as a novelist, but you improve the odds by writing genre.
19 or 57% of class of spring ’77 wrote at least one genre novel:
17 wrote mystery/suspense
3 wrote fantasy/sci-fi
1 wrote a western.
All of the most-published authors wrote genre:
Brooks has published 26, all but one fantasy.
Chesbro has published 23, all mystery/suspense.
Jackson has published 11, all but one mystery/suspense.
Authors who wrote wholly or predominantly genre books averaged 6.7 published novels, considerably higher than the 3.6 of non-genre writers.
(Note: There were romance writers around in the '70s, but the genre was not as dominant as it is today. Perhaps Library Journal did not invite authors of first romances to contribute a statement.)