I have congenital deformities in my hands and as such I've had a LIFETIME of braking with the FRONT brake only. I need the other hand to hang on to the handlebars as tightly as possible.
Issues such as locking up and sliding or going over the bars are real, yes, yet in the scheme of things minor. You just learn how to use your brakes properly. If you have the luxury or running both brakes off on lever then go for it. One brake only? definitely the front. No competition.