It's obvious the above person is not a lawyer because a lot of the info is incorrect. But he/she is right about one thing, though not totally acccurately stated--a lot of people regret attending law school/becoming lawyers. I'm one of those people. I do know lawyers who seem to enjoy what they do. I think the reasons why depends on the sector and/or type of law practiced.
People I know who worked in public interest seemed to really care about helping people and the kind of issues for which they represented clients/helped clients obtain representation. In addition, at the place I worked in the public sector, we had relatively great hours and there was more freedom as far as coming/leaving when you want.
People who work in the private sector seem to hate what they do more often, but the ones who don't, or who admit downfalls but seem to feel like it's worth it or tolerable, enjoy the money and the prestige. What's best about their jobs to a lot of them has nothing to do with the actual work, although a relative few really do enjoy that aspect, as well.
Being a corporate lawyer doesn't mean you represent a business/company. You can be a corporate lawyer at a law firm that takes on clients from businesses or actual businesses in various situations, which actually seems more common to me. From what I've been told by other lawyers, they work crazier hours than litigators, except maybe when litigators have to prepare for trial (and that's less often than a non-lawyer would think). At law firms, they still deal with billable hours, but maybe not as much of the boring legal research/writing that a litigator or law clerk would. And at major law firms, salary depends on how many years you've been there, at least for the first years, but is still high...up in the chain, it might get uneven because law firms often hire people away from other places and might need to make a more attractive offer. Lawyers at smaller firms don't make good money.