I'm going to take a bit of a different tack on this. I've worked in a lot of startups and never once have I worked in a company where the founder knew what they were doing from a technical sense. I'm sure they exist, but they aren't common.
What most successful founders are good at is running a business. However, I'll be really clear on this: there are 2 necessary things without which you will fail. First you need someone on staff that does know what they are doing. If you are good at recognising that person, then you've got some potential to be a good founder. Second you need to be flexible in your vision. Because, as founder, you probably don't know what you are doing.
One of the best companies, in that regard, that I worked at was Corel. Michael Cowpland was an engineer, but I've talked with him a few times and I'll just say that I've never been that impressed with his technical grasp of the situation. However Corel's first product was a SCSI card. It failed. Then they built a graphics card. To go with the graphics card they made a graphics demo. That demo became Corel Draw. Cowpland had a great ability to know when the spaghetti was sticking to the wall (and he threw great gobs of the stuff against the wall, let me tell you!). They just dropped everything and poured everything into Draw. Great move.
The "fake it till you make it", in successful circles, means to stall long enough for your development team to actually build something you can sell. Now, I will say that committing fraud as a way to stall is a stupid, stupid move, but not something I haven't seen before. One place I worked at we were late to demo our product at a show, so we bought the competitor's product, stuck it under the pedestal and then wired it up through an empty box which was supposed to be our hardware. People were astounded at how quickly we had caught up to the competition! BS stuff like that happens all the time and especially if you are young, it would be easy to think "Oh, everybody is doing it. It will be alright. We'll succeed before anyone notices".
I don't know enough about Theranos or Holmes to say anything intelligent, but being a founder is a very different job than being a developer. What I lovingly refer to as "blowing sunshine up everyone's ass" is a big part of the job. Your core competencies are really different and have to be geared more towards evaluating people rather than evaluating things. At the same time you have to be an anchor of calm in the middle of chaos, because if you start to freak out, then everybody else will to. A lot of the advice given to founders can easily be misinterpreted when seen in a different context and I think that may be what's frustrating you. Having said that, being an entrepreneur is a career that attracts more than it's fair share of people who are not suited for that career...