I struggled with a similar question to this when I first began working, and I think my own answers to that one will help you in answering this one.
First, the way you framed the question implies many external motivators for work don't match with the possible rewards, when in fact a lot of people who are sweating hard for someone else's dream are driven by internal motivators. Why not put your all into what your do, regardless of who benefits the most? I guarantee you, you will gain a lot of insight into what your capabilities are when you find out your maximum operating capacity. At the very least, when I see someone that puts enormous effort into something they don't necessarily believe it, it makes me contemplate just how much effort they would put into something they truly do believe in.
Next, to completely demolish my last point, I came to understand that all of these internal and external motivations were very weak when it came to whether or not I'd execute on something. The truth, as I see it, is that motivation is like having a sailboat which rely on strong winds to blow you in one direction or another. When these winds die down in one direction, you start steering your rudder towards another direction that can return you to the same level of progress towards your goal. Instead, the key is having discipline, which is like having an engine that could push out in any direction no matter the state of the wind. These startup environments are one of the ultimate areas to test and strengthen discipline, as you have to push the limits that most people would shrug off as impossible work conditions. Succeeding in that environment is also a means of building your confidence up in order to take on larger tasks, such as starting your own business.
It's also possible that a lot of the people you are seeing working long hours are doing so because they're optimizing for long term gains (such as increased job skills, more company responsibilities, startup contacts) which will increase the likelihood of their startup being successful when they do strike out on their own.
The NSA doesn't opt out of pay scales -- all general employees follow the GS pay scale with GS 10 removed (GS 9 promotes to GS 11). For those with a degree in certain fields, they follow an increased pay scale but along the same grade. For instance, someone with an electrical engineering degree would follow the GE pay scale, which still has the same path (GE 9, 11-15) but makes something like 2-10k more per year.
The biggest difference, is that their promotion structure is split into two parts: there is a technical route to promotion and an administrative route. This means that you can either be good at being in charge of people and get promoted (administrative), or just be good at what you do (technical). It leads to interesting situations where a GS12 is put in charge of divisions comprising GS15 veterans of 20 years experience, but all in all it is by far the best government run organization I've worked for.
First, the way you framed the question implies many external motivators for work don't match with the possible rewards, when in fact a lot of people who are sweating hard for someone else's dream are driven by internal motivators. Why not put your all into what your do, regardless of who benefits the most? I guarantee you, you will gain a lot of insight into what your capabilities are when you find out your maximum operating capacity. At the very least, when I see someone that puts enormous effort into something they don't necessarily believe it, it makes me contemplate just how much effort they would put into something they truly do believe in.
Next, to completely demolish my last point, I came to understand that all of these internal and external motivations were very weak when it came to whether or not I'd execute on something. The truth, as I see it, is that motivation is like having a sailboat which rely on strong winds to blow you in one direction or another. When these winds die down in one direction, you start steering your rudder towards another direction that can return you to the same level of progress towards your goal. Instead, the key is having discipline, which is like having an engine that could push out in any direction no matter the state of the wind. These startup environments are one of the ultimate areas to test and strengthen discipline, as you have to push the limits that most people would shrug off as impossible work conditions. Succeeding in that environment is also a means of building your confidence up in order to take on larger tasks, such as starting your own business.
It's also possible that a lot of the people you are seeing working long hours are doing so because they're optimizing for long term gains (such as increased job skills, more company responsibilities, startup contacts) which will increase the likelihood of their startup being successful when they do strike out on their own.