There certainly is a "correct" way to play most instruments, but this is Rock and Roll so "correct" doesn't always mean much or sound best.
On the other hand, the guys who know music theory and have learnt a good technique will always be better players, think James Jamerson, Nathan East etc.
PS one finger per fret is not as good a technique at the low end of the neck, as you found out. 1,2,4 is much better.