Don't let the naysayers spoil your dream! That being said, be smart. Don't try to reinvent the wheel; find bloggers and webmasters that are successful and mimic what they do. The web is just like any other business; 99% of people who try, fail. But if it's really your dream, be part of the 1%. I can tell you; there's nothing more satisfying than having a website based on your passion.
The trick to making money is to find out what people want and go get it for them. Don't think that any idea is so cool that of course everyone would want it.