Would you give years of hard works freely to someone who just waits to gain benefits from your hard works? Majority of the answers will be NO. Therefore, a patent system is still needed in order to protect inventor's hard works from being stolen by big sharks.
However, there are problems with the current patent system. Why Innovation is stifled. Why trolls and litigation are likes wildfires. They all come down to one root cause. The current patent system treats all patents the same and does not factor in that the speed of the innovation in each industry is different.
If we just look at the innovation speed of the software industry and the 20 years patent length, the problems mentioned earlier become obvious. Say if the software patent only last 5 or less than 10 years, the problems become mitigated. Trolls will need to justify the litigation costs vs revenue generated in less years. Many paper patents will become no value at all.
Also, because the patent length is shorten to less than 10 year, it’ll force inventor to wait until implementation or commercialization of the patent is mature before filing the patent application. Otherwise, by the time implementation or commercialization is ready, the patent will most likely due soon.