Speaking as someone who recently did a round of interviewing with a mix of established companies and startups, $50k is a _very_ conservative guess. The difference between my Google offer and the highest startup one was ~$100K - if you drop to the average startup offer, it goes up to ~$150k. And that was at ~3.5 years of experience - it gets worse as you become more experienced.
It's hard for me to imagine how sure of a bet a startup would have to be for their equity to be worth $150k/year.
That said, this is makes sense to me. Google's stock options aren't making employees wealthy these days. Yet it's still a fantastic company and obviously compensates with salary. On the other hand, no startup that I know of can pay 3-400K salaries for 3-4 years exp.
Also it should be said that the type of work you likely do and the culture at a large public company will likely be very different from a small startup. Culture, ability to influence direction, large potential upside (though unlikely) are reasons people continue to pick startups despite lower salaries.
I'm CEO and co-founder of a funded company. We pay competitive salaries + options. I don't begrudge someone who isn't interested in options. Options are actually expensive to me. We are still fairly early stage (Series A funded) so the founders own most of the company and the option pool primarily dilutes the founders. I want to give options to someone who wants them. I'm fine paying more salary in lieu of of options.
I think of options like a profit-sharing plan in a mature company. If the company does very well then the employees should share in that success. Some folks feel that paying very low salaries and heavy options breeds loyalty. I personally don't subscribe to that. I prefer to pay something competitive and have options as nice upside for the employee.