Keep in mind you're gimping the developers money by doing this, plain and simple.
That's only true if I would have bought it at full price in the first place. Pricing is always a negotiation. I want the most value for my dollar. They want the best price for their item. We make a deal when we agree the price is right. In these cases, they get my purchase now rather than waiting for a sale later. I'm also giving up my, admittedly limited, return rights under Steam.
If I want to support a developer, I will happily do so. I've even been known to pick up some ridiculous collector's editions. I'm looking at you my Homeworld remake Mothership. Let's not even get into Kickstarter.
I do appreciate the input.