In an age where it is becoming increasingly more and more difficult to make it big as a musician, is it really such a bad thing for an artist to take an opportunity to get their name and music out to the masses? For one thing, it costs money to make music. There is just no way around it. Instruments, gear, studio time, promotion, etc. isn't free. Any of that that is is probably not going to be all that great and won't help you all that much in the long run. You can't keep the lights on and doing what you love on artistic integrity.
That being said, why is it considered artistic integrity when you pass up an opportunity to profit off of your passion and get your name more recognition? Is it somehow cooler and more honest to stay in a crappy basement and barely get by, only playing the pitiful local stuff in your area? The way I see it, you're only shooting yourself in the foot by doing that. You're stunting your growth as an artist and preventing yourself from having more opportunities in other areas of life as well. In that sense, keeping yourself in a box like that is the opposite of artistic integrity because you're just doing the same thing over and over again and not evolving.
I'm in an up and coming band myself as many of you may know. I have absolutely no qualms with anything that might come our way that would make us money and/or give us the opportunity to get our name further out there because we want to have a larger audience and we do want to get to a point where we're making a living out of this. I would LOVE if some fat cat corporate person came knocking on our door with a huge check and an offer to put one of our songs in their advertising campaign (as long as it wasn't for anything illegal/immoral). We would be able to gain exposure and have a bit more cushion in our living situations and collective artistry. We could grow as artists due to the opportunities afforded to us by such a thing.
The only point where I would consider selling out a bad thing is when you change your music in such a way that you're only making that way in order to make more money and have a wider commercial appeal. It's one thing to change your sound because that is the organic direction you're going in. It's another if you're just doing it to put more zeroes on the left side of the decimal point in your bank account. At that point you have lost sight of what being a musician is all about in the first place.
All in all, as long as the music you make comes from the heart and is honest in every fiber of its being then as far as I'm concerned you should sell out BIG TIME. Take every good opportunity you can get if its offered. It's tough out there these days and if you can catch a break then don't let some hipster tell you you're wrong or bad for accepting it. Make all the money and get all the exposure you can. There is nothing wrong with it.