Like I said in a comment, it's been a while since I've taken an economics course, but a couple of things stand out to me.
could we not each of us be wholly self sufficient
We can't be wholly self-sufficient. As developers, we have dependencies on other companies to do things that we simply can't afford to do on our own. We depend on computer manufacturers (or at least hardware manufacturers) to produce the hardware we use. We depend on ISPs to provide access to the Internet. Software developers also depend on each other. We depend on other computer scientists and software engineers to produce the tools that we use, from the operating systems to the languages. No one person has the knowledge to build and maintain everything on their own.
and not just wage earners
Based on what we do, we have to earn money. Writing software doesn't (by itself) provide food, clothes, shelter - any of the basic human needs. Instead, we have to rely on the needs of other people and then create or maintain software that meets those needs. In that sense, we rely on other people to create a need for software that we can fill.
I agree with Satanicpuppy's response, however. The barriers to entry are extremely low. Most people could probably learn how to write software, whether that's scripting an existing application to make their life easier or being part of a large project team developing things on the scale of the code that runs a Boeing 777.
I think that the community that I mentioned above is key. No software developer works in a bubble. From open-source projects like the Linux kernel to large closed-source projects made by Microsoft, Apple, and Oracle, there's always a team. Some projects started off as an individual's idea and a large number of hours put into it, but in the end, the contributions of dozens or hundreds of people make software possible.
But in terms of owning the means of production (in the way I understand it, anyway), no - I don't even know if that's possible in today's world for anyone. But like I said...it's been a while since I've looked at economics.