I have another reason for the old-fashioned approach. I do hedge fund accounting for a living. With my software tools I can reproduce every result ever created for a fund from original input, even going back several years. I have translators for various brokerage feeds that I've had to maintain and adapt for years -- and this is no small feat considering that information technology people in the financial industry can't do a complete, consistent, or stable data feed to save their lives.

Whenever I make a change, either to a translator or even the core accounting code, I make a copy of the library. I then have to go back and run all funds, including my test funds, as a regression test using the new modified library. I have to do that one fund at a time, testing to make sure no catastrophic differences have arisen. So during this interim period, I have some funds running on the new code and some funds running on the old code. BOTH versions have to be "live" at the same time.

I also have to keep backups of the data as well, both inputs and outputs, so I can "diff" those easily. I'm sure as heck not gonna put that into git.

So I'm not just stick in the mud trying to be contrary -- I have work to do, and it needs to be as reliable as a Swiss watch.