Patents do provide incentive for innovation and invention. While Benjamin Franklin may not have patented his designs, the vast majority of inventors did. Eli Whitney, Nikola Tesla, Thomas Edison, the Wright Brothers... They all patented their works, and hence were able to make a living as innovators; Benjamin Franklin, on the other hand, was a statesman first and foremost, NOT an inventor, and hence his inventing was more of something he did in his free time. And it can readily be argued that his inventions were hardly as revolutionary as many others that came after him; so really, without the protection afforded to patents, we would've certainly not been in quite the same technological age today. So no, the argument that a lack of patents would've meant more progress is utter falsehood.
Patents are perfectly fair, and operate on a reasonable principle: if someone manages to invent something, and spends all the resources to do so, then by all means they should have the ability to profit on it for a limited duration. Mind you, for those confused, patents do NOT last anywhere near as long as copyrights; the current term length is 20 years from the filing of an application. It used to alternatively be 17 years from the date the patent was issued, an alternative that was removed because it was exploitable. (so yeah, in other words, law shifted to make patent coverage SHORTER) Also, patents aren't exactly close to as free as copyrights are; they cost a sizable sum, generally into the thousands of dollars, depending on their length; so a small-size inventor can at least afford a few years of protection to really get the most important part of profiting from their invention, while larger corporations will, often enough, find that their patents filed for maximum length, will often cost them MORE to maintain than they are making because of the patents.
For those that don't like patents, don't use them for your own creations. Sure, you can make all your stuff public domain/open source, but then you won't also be making any money off of it. But for those that want to be able to actually get a monetary reward for all their effort put into creating an invention, patents actually help ensure that the large corporations can't just scam them, and use their massive amounts of money, power, and influence to make it their own. And lastly, to get a patent, you must explain and detail your invention, making sure that once the patent expires and it goes into the public domain, there is no chance for the new technology to be lost.