Patent law that allows software patents is already seriously messed up and urgently needs fixing. When it allows patenting programming languages, it's outright sick.
Software based inventions aren't special, they are just new to the game.
From what we see, software patents have caused more harm than good, but would be great if there were enough concrete public examples listed somewhere that prove otherwise.
They are special enough to cause serious harm to progress if patented. This was demonstrated many times. Since the whole point of patents is to promote progress, software patents should not exist.