We never made any money, and I was the only permanent technical staff (but also technically the CTO) but we had some amazeballs clients - Samsung, Siemens, Tesco, RIM (while they were still cool), and so on. When we stopped being able to pay me a salary, I turned it in to a real CTO job at a 150 person software company. Our client list gave some real credibility there, as did being able to talk a good talk and lookin…
Because there are so few 150 person companies, most CTO jobs are for small companies.
This doesn't make them any less of a CTO job. In fact, the hard decisions for a CTO are often going to be at the start. Choosing the stack, building the initial team and engineering culture...
So stop questioning yourself.