The incentive to create is in the money you make from having written and either sold the service that you're selling, or selling the software itself, or sometimes just from the good feeling you get from having made something that works. The latter item is what inspires most really good folks, honestly.
Patents are horrendously ineffective at their intended purpose of incenting innovation in a world where non-practicing entities (read patent trolls) have a vast number of patents and exist with the *sole purpose* being to get money from those patents, and NOT to actually use them. Often the patent is granted (with the application having been secret) years after others have independently gone and done the thing themselves, thinking it was no big deal, probably because *it was no big deal*!
Even worse, many patent holders wait to sue until the idea (or company implementing such) is successful, maximizing the damage.
Worse, most of the patents these days (and there has been an explosion of patents... why orders of magnitude more patents when we're arguably no smarter than we were 10 or 30 years ago??) are fricking obvious.
And of course there is the fun bit that NO COMPANY CAN DO A PATENT SEARCH BECAUSE THEN IT WILLFULLY INFRINGES AND MUST PAY TRIPLE DAMAGES. So, noone looks at patents who actually might use them.
Patents, especially in the realm of software, do more harm than good today.
Strike that. They're almost purely harmful.