I hate that "money" is nearly taboo to talk about. When considering a job, compensation is very important to me. Honestly, it is probably the #1 factor. Other factors matter a lot as well but they are usually only guesswork when at the interview/offer stage. Things like "office environment", "mission", how I get a long with my co-workers, etc all are important but what they tell me up front and what I imagine in my mind's eye might not turn out to be reality. But the money part, that is set. When they say $100,000/year, they pay it. Now we are talking start ups, so obviously equity is a different story. But you can still run the numbers and calculate what you will make depending on the size of the exit. I am not opposed to some risk for the reward (equity vs. salary) but if the reward is 10% of one year's salary if we sell for $100 million dollars, then why should that interest me? Sometimes they make those offers where you can choose more equity or more salary. Maybe I'm just insecure but it's as if taking the salary option says something about you and your commitment to the "mission" negatively. In the scenario I laid out above, I'd say it just meant you can perform simple arithmetic.
It's not taboo, most people just think it is, especially in industries where there is a lineup of qualified applicants.
I pick salary every time, the equity is fuck all in most cases. There isn't a mission, it's a job, in exchange for my time I require money, as the founders will say they are taking most of the risk, so you should get most of the money.
Dealing with these questions upfront is the way to get rid of people who don't know what they are doing who are wasting your time.
If the business is wildly successful as the founders claim it will be then they should be encouraging you to take less equity rather than more. No sane investor only invests in one startup, which is what they are asking wrt equity. It's far better to make lots of money and invest that money in a variety of startups.