Well, you say that the software wouldn't be written, but then I don't believe this. Just because someone wants a monopoly on an idea, doesn't mean it can't be useful to make someone else money. If the idea is valuable enough, then someone will make a product from it. Then someone else might improve it, or make it cheaper. That's competition, in a free market.

The funny thing is, if software patents were only for 5 years, then it's unlikely this would be a story. The market could be capitalised on still by first-movers, and then competition and those who want to contribute further to society could cool their heels, even study the designs, and move product for consumers, and provide additional jobs. Mass market distorting giants couldn't get unfair advantages and innovation would thrive. The technology would improve because then that same company could file improvement patents, but not stop the old patent from being used. Patent trolls would not be a thing, or at least a very limited thing and at the very least all easy processes would be documented.

Teams of PhDs would still invent things. We'd still have cool tech. Open source people would make amazing things. Matheticians would continue collaborating. The world of commerce would not come to an end.