It's the argument I made yesterday in a related thread: if the screen reader can't read it, the machine can't read it. Any machine, whether it's the Turing machine that's trying to make heads or tails of your website so it can read the text to a user, or the actual machine running in some Google data center somewhere. Or the machine running your script to make life a bit less of a series of button clicks.

If that doesn't convince you, then have some pride in your craft, some attention to detail. Visually impaired users aren't the only ones annoyed by the fact that you couldn't be bothered with tab order. We have tools, you don't need me to tell you that you're lazy (or overworked, or underbudgetted...), the machine will do that for you.