Not necessarily founders but BigLaw has partners at various levels and then associates plus various support staff. And, yes, BigLaw (like investment banking) has a reputation for really working associates hard in addition to having something of an up or out structure. Which probably works OK for law because a lot of the associates probably went to law school because they weren't sure what else to do with their liberal arts degree--and don't necessarily want to stay in law long-term anyway.
Up or out is right. But the most common “out” path is to a corp legal department. Better hours, and now the partner that used to work your ass off buys you lunch to court your business.
Yeah. Though I know a lot of lawyers who migrated into non-law positions after a few years, including politics (also usually for a few years depending on their leanings and the climate--e.g. White House) but also a variety of other things. As you say, there are also a variety of corporate legal positions including government affairs and the like in addition to straight law jobs.
