It has nothing to do with entry level and more to do with entry cost. Basically, it costs nothing to "get into" online porn for anyone who has the motivation to do so. No cost, no risk, plus you get to jerk off as you please, so it's more like a game and difficult for most people to treat it like a real business.
If "real world" businesses like car dealerships, restaurants, and electronics stores required zero investment or risk, the economy would be fucked.
