Yes and no. I agree should expect zero to come out of it, as it's a pretty low probability you'll see anything. But you still have to do the work of valuing it.

First off, the people you're negotiating with see it as valuable, so it's a very bad negotiating move to say, "Keep your dumb equity and just give me cash." You'd be slightly better off just pointing to their family photo and saying, "Wow, your kids are ugly." Second, going through the work of valuing equity is necessary to see how the investors (that is, they people actually paying your salary) look at the company. Third, on the off chance you are successful, you're going to really wish you took the equity part of the negotiation seriously.