It could take 5 years at university to get it working at all, 5 years as a startup to get the first product to market, 5 years to scale up the marked from zero. Then you only have 5 years left where you actually have a chance to make money.
Shortening the patent life to even 10 years would make it unattractive to patent groundbreaking technology.
If you immediately make it to market, the story is different. In the software-sector everything is moving much much faster than in the physical world. The negative effects of patents become much more obvious then.
One way to go about that is to limit the license fees the patent holder can get. This would change the game in major ways (mostly for the better I think).