Why on earth would IP keep bad ideas around? You're free to make a better idea and let it compete in the market, since by being better it'd definitionally be different.
Let's say someone patents, idk, Client-Side Decoration (CSD). People like it, surely, because people use it. Unfortunately, there is drastically reduced space to innovate because nobody else can use that idea anymore. Expecting the patent holder to innovate has proven to be a bad assumption in part because IPR means they have no competition in that space anyways. The idea stays bad because nobody else can make it better.
For the same reason any accumulation of capital allows bad ideas to hang around. You can operate at a temporary loss to weed out new competitors, you can intimidate newcomers with frivolous legal action, you can leverage network effects, you can lobby for regulation that makes it hard for competitors to start up...