That's not entirely correct.

yes it gives little BP, but the effect of high % purified attributes can come in very handy.

I have 97% initiative purify on my blade pos 1. To get +90% is already rare and difficult. Extra 3 pills I can make my pos 1 initiative 100% effective.

100% effectiveness can apply through control and critical. That's why you might see sometimes your enemy failed to control one of your unit.

Don't judge pills on little extra BP, but look it through its effectiveness that would come to play in the game.

BP doens't always mean everything.

I don't know if you play LoL. For example when adc builds 100% crit, it's guarantee double of damage output.

However that would be deducted by other factors such as def and injury in this game.

Therefore when you do your refine rebate. Hold on to your pills and use it on your best purify. It's hard to obtain for us who don't spend cash in this game.