Execution and the skill of your team is of course important, but there's little execution without money. The wealthy and established get a head start on execution by virtue of their posistion. It's not impossible to succeed without backing, but it is more difficult. I can understand why people want to protect their ideas. Companies like Google/Microsoft could get a product built and used by millions within months of having an idea. Additionally being the 'first mover' is often critical in the success of software, so you'd want to ensure you have enough of a head start before competitors start copying you.