Press The Attack is not fulfilling its designed role as teamfight enhancer

Instead marksmen and the occasional jungler are taking it as a burst enhancer.

Why don't supports take it?

Supports don't build AS, so three autos is unrealistic. You'll be dead by the time you get them off. A tank support might be able to do it... if it weren't for the fact that they're all melee and have to close the gap first.

Why do marksman take it?

Because it provides more burst than Electrocute, while also enhancing your DPS in longer fights. It makes it both easier to pop your lane opponents in bot and melt the enemy tank jungler or top laner during teamfight phase. It's good in any phase of the game and against any opponent.

Solution to both?

Remove the damage, making it only good for enhancing teamfights, then make it far more consistently available. Either two autos or two hits to proc. Even without the burst damage, being able to apply it consistently will make it OP (8%-12% is alot, ask anyone who uses Cut Down what just 5% can do over an entire match), so you'll need to nerf the damage enhancement too. 4-12% might be a good place to start.

The idea is to take it from "good overall rune for enhancing your damage at all phases of the game against any target" to "rune for making enemies you and teammates have piled onto die faster". Less personal power and more teamwork power.