Think about it from investors point of view - why should they give their bitcoins to strangers, even if they present some very good business plan, if there's always a huge risk that it's just a scam? Banks have legal power to take back what is owed to them, but in Bitcoin there's no such opportunity. If banks don't give you loans, seek angel investors or VC, try some fiat crowdfunding platforms like Kickstarter.

Also, there's a board on this forum for pitching your projects to potential investors, you can try your luck there.