I think there is some truth in this, at the risk of generalising.
I think that the ratio of professional/hobbyist differs between commercial and OSS operating systems: Windows tends towards professional and OSS tend towards hobbyists, not sure about Mac.
(before the knee-jerk replis come in, I know there are professional OSS users out there, it's the ratios I talking about).
Why does Windows have more professionals? I think that a lot of companies don't trust things that are cheap/free. I heard from an old boss a story of a trip to a software/hardware conference for a specific vertical market: a new vendor wasn't getting any
interest in his cheap product, after taking advice he multiplied the price by 10, suddenly potential customers started to take him seriously. It's weird, but it seems to be true.
I think that professionals tend to view their software as a tool to get the job done, while hobbyists take it as a religion. The different in professional/hobbyist ratios shows in the 'culture' of the specific software.
There are zealot on both sides and calm professionals on both sides, it's just that the balances are different.
Excellent answer Herbie.
I think you're completely right about the ratio's between professionals and hobbyists, based on industry.
I'm a techy at a manufacturing company, and we run an almost 100% windows enviroment...except for one office where we have 6 Unix workstations and a legacy
(pretty much) Unix server, purely because it was the best tool for the job at the time. But now we're moving away from Unix in that office and over to windows, not because Windows is better, but because no one can support the system anymore, and it makes
sense to bring it in line with the rest of the company. The unix system is a lot better, but no one here can support it anymore, so we've got to move away from it