I think you are missing his point. His point is not that patents should not exist, it is that patents are not protection of ideas. They are protection for inven

I think you are missing his point. His point is not that patents should not exist, it is that patents are not protection of ideas. They are protection for inventions, as in, the actual (used to be physical) functional embodiments of an idea. If you allow someone to patent cotton gins just because they thought that they sounded swell and wrote the idea down, you've seriously hindered any kind of market at all. Your idea is worthless without an embodiment, and no one else can make anything until your patent expires. If you allow someone to patent all cotton gins based on their single implementation one, you again have poisoned future implementations -- perhaps better and more efficient ones with completely different physical forms -- just because they belong to the idea class of "cotton separating machines". The point is a very important one: ideas are not property. We can go a little further and say all IP is not property either. You cannot be deprived of it (short of a lead pipe), but you can be deprived of your granted right to profit from it, for a little while at least. That's the motivation you speak of, and that's the only reason patents exist at all, at least in the US.