I find this true, but also based on initial influences as my first teacher was a one finger per fret guy, who stressed the importance thereof before venturing onto scales up the neck. 4 finger work on bass he felt, was a primary skill.open strings are harder to control, they also sound different. Your tone is more consistent when fretting all notes. zero fret anyone? Obviously E & B are exceptions.
If you go back in time, there were a lot of 3 fingered claw players who strummed with a pick, probably more today, but its more accepted these days.
