"You can do more - when you see their idea, and their way of doing it you can simply think of a new way of doing it."
Their idea? I thought that mere ideas weren't supposed to be patentable.
In fact, a lot of patents in the software and user interface domains are vague statements about how the "inventors" could do something but haven't, or maybe they have done something but won't describe it properly, yet still want a monopoly on that thing anyway.
And in those domains, a lot of people come to the same conclusions about what the new ideas are and how they should be implemented independently, so giving some people a monopoly is unjust to say the least.
Patents are a great way of sustaining a bureaucracy that has nothing to do with innovation. The money locked up in feeding that bureaucracy and litigating its products would be better spent on other things like, for example, actual research and development. That's if that kind of thing actually matters to you, of course.