Everything you say is correct. But on the other side of the ledger, the later Box employees presumably received market-rate salaries, and I suspect that many of the 1,200 employees are salespeople who may well bring in more in commission than the average software engineer makes in salary.

Also on the other side of the ledger, I could rewrite your comment to:

A founder at a tier 1 company might have millions of dollars in shares, but it'll go down quickly from there for everyone below the first tier. What about the founders at other companies who chose that route over safe, comfortable market-rate salaries and failed, or who received nothing after a down round with a high liquidation preference? Where's the WSJ article on them, and the thousands of others who are never written about when a handful of Silicon Valley companies a year go public? The ones who started a company, with their personal finances in the red, or under pressure from all sides, and helped it grow and succeed... and they walk away still not being able to afford a house in Mountain View, while early employees at Box or Facebook or Twitter pick out colors for their Ferraris?