I put all mine into VIT on sch cause the fairy does a bulk of the healing and abilities like lustrate ignore MND.
A healer with 4200+ hp can carry some very bad HM primal DF groups, get shanked twice in a row by WP tonberries and live etc.
Ive watched some JP healers play with 4500+ hp and at first I thought it was kinda dumb to allocate+gear so hard for VIT but its an amazing alternate build with a buffer for when things go super bad or you play in mixed company.

As time goes on and iLevel and stats inflate more, the customizable 30points will be even less of a factor. You do not have to dump the points into your 'primary stat' to function competently at your job.
Racial base stats have a +/- 6 point stat range, you don't see people shouting for only certain race+job combos in this game do you?, chill.