Why can't a competitor pop up who is backed by more respected, well known investors, promise to limit their money supply to 1/2 of that of Bitcoin's, and eat Bitcoin's lunch?
It's called Ripple.
![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
(except for the limiting coins thing)
The problem is, the only way you will get millions in advertising is if it's backed by a commercial entity; a commercial entity has to make money to justify its existence, and it wouldn't be possible to make something as popular as Bitcoin if there was a bottom line to worry about.
What are the things people don't like about Paypal? Fees and arbitration. But how could Paypal exist without taking fees? And they probably wouldn't get away with ignoring claims of unauthorized payments, etc.
You can see similar problems with Ripple: the currency is 100% premined, and the company is holding a huge amount of the currency in case it becomes valuable. For that reason alone a lot of people are turned off by it and it's having a hard time becoming widely adopted by the Bitcoin crowd.
(Note to self: Look back at this post in 2 years when Ripple is the only successful cryptocurrency left standing and slap palm to face)
I guess in theory, you could say Satoshi created bitcoin to get rich on the coins he mined in the early days. But he didn't invest millions to advertise bitcoin, so no one thought that was his motivation. In terms of creating a popular cryptocurrency AND keeping your financial motivations hidden (or having none), the first mover advantage goes to Bitcoin alone!