As a solo developer, I guess I’m going to start tracking how fast I type and the size of my code commits each day, and that, my dear IRS friend, is the only part of my day I spent “developing software.”

The reality is that even if you hire a “software developer,” they aren’t going to spend 100% on it. So now you have a situation where the IRS is supposed to audit how? Watch how much support you did? How much training and coaching other developers? How much email/scheduling/admin bs? Was that meeting about software development or customer research? The fools who write these laws are just ridiculously out of touch.

That's not what this is about. It's to do with a situation where companies were trying to make the IRS believe that money they spent on S/W dev was a valid R&D expense (so they could claim some R&D credit and hence pay less tax), and the IRS said "nope, that seems to be not valid because we don't see S/W as really R&D". So...some campaign contributions later and voila there is a law saying definitively that S/W does count. Those companies asked for this change. Now, possibly the whole thing got lost in translation and became a terrible bad thing, but most likely not. Often these things need to be read in the context they apply, which is not "globally".