Why is software special? Why is all other payroll not treated like this?
In reality, this is something made up to balance a budget while pushing the consequences beyond the next election. It isn't a well intentioned accounting principle
It’s not just software. Software developers are just the most vocal people talking about it. I worked a company that owned nuclear power plants. We did R&D on how to make the power plants work more efficiently and safely. Some of the work we did qualified as R&D and could be capitalized. This mattered as the US government gave tax credits for eligible R&D. The tax credits directly reduced your tax bill.