It still is abused for short indie games, with people buying them with the intention of speed-running through and refunding.

The refund policy is intended more for “crashed repeatedly”, “far too slow despite my machine matching the stated specs”, and “simply wouldn't run”, type problems, rather than not liking the game. There isn't much a service like Steam can do about that, that won't be abused, other than offer demos (enough for you to try out those core mechanics) which is really down to the game creators and out of their power. Other than that you just have to not be first in line, and wait for reviews from sources you trust.