It's funny how trying to sell software for linux just doesn't work out well. Almost like Karma is a coder. I hate to break it to you, but there are tons of for-profit software written for Linux--some is written only for Linux.
Just because Daniel can't figure it out does not mean that it's a bad idea.
Daniel inadvertently explained why it was a bad idea. Putting money into building a structure to support dozens of distros, all the while knowing that if your program is worthwhile it will eventually be
recreated by the open-source community and distributed (and supported) for free, is not generally a part of a profit making plan.
Just because someone wrote a piece of for-profit software doesn't mean they made a profit on it. Of the tons of for-profit software you mentioned, what percentage of them would you estimate actually made a profit?