I was thinking more along the lines of competitors who are in the same space as you (let's say, light bulb manufactures) -- you patent a new type of bulb, your competitors could patent a bunch of improvements on it to deny you future market on improved versions.
Your competitors will patent improved versions if you don't. They might also invent a product using a new implementation leaving you with no market.
And in practice, it doesn't work that way. Companies acquire patents on each minor upgrade to their technology.