I always considered being "founder" status to indicate you have NO salary. At least in the early stages. You pay your bills, then every dime you have left you put back into the company. Basically, the startup is your life, with all of your financial incentives being driven by your equity ownership.

But maybe you are referring to early startup employees? I can see what you say being the case in that type of situation, where salary is typically low in exchange for more equity.