They matter for exactly 2 classes: WAR and SMN/SCH.

WAR, at a certain gear level, benefits more from having 30 more STR than it does having 30 more VIT.

SMN and SCH just get the hose since they both share the ACN class and therefore the ACN class' bonus stat allocation despite the two jobs requiring different stat priorities.

It's a ridiculous system. The only option it opens up to players is the chance to do something wrong.