That is not at all the question. The point of patents is supposedly to protect inventors and innovators. There is no question that it will (short term at least) hurt consumers; a limited monopoly means a higher price and fewer competing products (if any).
People don't argue that patents are good for consumers because they aren't. People argue about if they're good for inventors and technical progress; if inventors will only innovate and share the results with the monetary benefit provided by a patent.
"People don't argue that patents are good for consumers because they aren't. People argue about if they're good for inventors and technical progress"
And the point of technical progress is to benefit the public (i.e. consumers) in the long run. So it all comes down to that.
The issue is in the implementation and outcomes. As you say, do inventors only innovate+share when provided with the monetary benefit of a patent? It would probably depend on the field, but I suspect innovation would still occur even with shorter patent protections for software design.
The point of patents is not to protect anyone, but to encourage innovation. It has become quite clear that patents make innovation harder (is impossible to create anything anymore without taking a big risk of infringing someone else's patents, and those with patents only use them to slow their progress by their competition, and to avoid having to compete/innovate until their patent expires).
People don't argue that patents are good for consumers because they aren't. People argue about if they're good for inventors and technical progress; if inventors will only innovate and share the results with the monetary benefit provided by a patent.