I'd rather work for someone who understands their employees are human.
Employment is increasingly a 1-2 year stint where workers are swapped in frequently and you need to get value out of them before they leave. But it really screws over people who are not known factors or who might need adjustments.
And that's okay. Startups are a little over-romanticized anyway.
You might be surprised by the hyper-focus abilities of folks with ADHD.
Keep in mind that your perception is skewed by selection bias — you probably already know many productive coworkers that never told you they have ADHD.
ADHD symptoms are a multidimensional spectrum [citation needed], and so-called normal people lie somewhere on that spectrum. Making affordances for folks with ADHD is a win for everyone. For example: write meeting notes and assign action items, use a bug tracker, ask people if the process works for them.