In general, underground music exists as a "pure" form of musical art. Not all underground music is necessarily better that Major Label music. It depends on what a listener is looking for. If you're looking for the best cheezy Corporate rock, or Boy band pop, you'll only find the best in band like the Backstreet Boys, or Journey. Furthermore, just because a band is "underground," by being that, it's not going to make that band good.

There are, however, very good bands and music that are created in the indie world. Bands that subsist in the underworld have credibility to create music that means something to them, rather than creating music that fulfills the bottom line as most Major Label acts must do in order to remain on the Major level.

I'd argue both ways on this issue. It's a gray matter, not a black or white one. On one hand, indie bands maintain creative control. They are not necessarily guided to create radio-friendly hits. However, limited by indie budgets, sometimes recording do not have the proper resources to present a good band in the best light, nor do they get a chance to be heard. Major Labels, on the other, afford some positive elements - distribution, and time to record. Bands have time to put more experimentation and creativity while on larger budgets, which may allow better possible records (if the label applies a "hands-off" approach to production). A lot of indie and punk bands have to run into the studio, crank out their best effort in the shortest amount of time. Sometimes the rush is good, pushing the live and more energetic elements of a band. But sometimes, it rushes the production of what just needs good old time to make happen.

What I do believe, however, is that you'll often find music that has more heart and truth to it in the underground, because it is often made in the raw spirit of haste (ie. you'd better be a good band to make a good indie record, you can't fix (punch-in/punch-out) all the mistakes and over-produce records like the Majors can, which may allow for a "perfect" record of an inferior artist.