There are plenty of good Bitcoin companies. The difference is that they don't sell their shares on unregistered exchanges to make money. If a business plan is solid and the management has a good background, then VC investors will gladly invest as there are several VCs focused primarily on Bitcoin.

Selling shares publicly before the company has even started simply doesn't happen on regular stock exchanges. The company first has to show their worth and then will be allowed to be listed to acquire additional capital, not their initial capital. Initial capital comes from the founders or VC / Angel investors. The concept used by most Bitcoin stock exchanges to accept IPOs for "just an idea" is silly.

Of course, there are exceptions to the rule (very few). Asicminer is the most prominent. They started their ASIC business from an IPO and have paid back dividends far above the IPO price (and the current price also exceeds IPO price). But when Asicminer started, there was very little in terms of VC funding for Bitcoin companies, so they didn't really have another way to collect money.