Worst in case of health insurance, the amount you pay is dependent on your income, not your actual actuarial risk. This means that, indeed, the healthy people working are subsidizing the costs of the ones "who don't give a flying toss".
And don't get me started on things like Künstlersozialkasse...
Don't know anything about Künstlersozialkasse - "artist social fund". Is that like a tax to (supposedly) support cultural activities..?
Why the distinction? Because this work involved Photoshop and mine used emacs?
It is only available to freelancers. People working in those fields usually don't have the option of regular employment. For that reason was decided that companies using their work still need to contribute to health insurance (as all regular employers need to do as well). For everybody else the answer is: seek regular employment if you want someone else to pay half of your health insurance.
Still does not explain why there is a distinction. Why do artists get to have companies paying them part of their social security while other freelancers still need to make this out of their own pocket? If this is a good idea for the artists, why not for other professions?
Furthermore you'd also need to take into account all the costs you can set off against tax liability.