You don't need a $250k salary to save $1mio in 10 years.
My rudimentary calculation shows you need to save ~50k in the first year, get 4% raises, keep expenses constant, and get a 5% return. Bonuses, options, etc are on top of that. Also, you could get step-raises in the middle for bigger promotions. And, you could marry someone doing the same thing and get there faster.
Or one can choose to believe actual data (see: published Visa related salary info, various government surveys, etc.), which indicates the average salary for these companies is somewhere around $150k (give or take). Sure, throw in bonuses and equity grants and some employees might top $200k regularly. Some very high performers are also going to regularly break $250k. I doubt anybody would debate that.
Let's assume the "big" guys (Google, Facebook, etc.) regularly pay average total compensation around $250k, so that patio11's remark is correct. So what? As many employees as they employ, they represent a small fraction of the number of people who are very well qualified programmers and engineers. Their salaries are by no means common. The market is good, but it's not that good.
You might have to live in the heart of the housing bubble to get that salary. A colleague who was very gifted at JavaScript was offered a job at Google but he was coming out behind after the increased living expenses.