I think the love of music is great, and I certainly have that, but I am also a professional composer, but I also understand that when you become a "professional" you have tainted your passion with money. Here's the thing - if you are "hired," i.e. someone has given you money to create music, you sometimes sacrifice creative control over a project.
This is NOT selling out in my opinion. This is a wonderful place where your musical talent is used to interpret someone else's needs rather than create your own vision. I love to do this and I hope my little rant is helpful to someone considering entering into music professionally so they understand that, yea, people aren't always gonna like your stuff, but you can prove your talent by interpreting THEIR vision and bring it to life through your creative medium.