I guess I'm preaching to the choir here, but a machine has re-sale value outside of what it produces, which is what actually makes it a "asset". This argument could be applied to any knowledge worker that makes a spreadsheet since you can sell the spreadsheet.
I'm not sure if I can follow your argument. A software dev usually works on something that is actually sellable (the spreadsheet software itself or a SaaS platform). If we take Facebook the platform as an example, for sure you could sell the software. Or a startup like Windsurf that gets bought because of the software they developed. So from my perspective devs actually create assets.
If there should be tax discounts to make it attractive to develop software is the political decision.
You are actually pointing out the difference between physical assets and intangible assets. Mailing lists are the classic example of an intangible asset. Trademarks as well. For clarity, the argument is that a firm could sell the software developed by engineers if it wanted to