Summary:
Gap closer (GC) potency combined with gap closers being oGCD reduces their utility as a movement tool to just-another-dps-button. This leads to unnecessary oGCD bloat and an extremely dissatisfying experience when missed GC opportunities happen in context. Feeling punished for holding GCs to use as movement utility should not happen.

Pros to removing gap closer potency:
Opportunity to use the ability as intended
Reduced oGCD bloat

Cons to removing gap closer potency:
Reduced overall damage
The "CRUNCH" feeling when you HIT with a gap closer

The removed 150 potency can be moved to other abilities, of course.

It would also be nice in gap closers did something that wasn't potency, ie. PLD charges to the target and absorbs the next auto-attack rather than the target of target.