I'm sorry you feel that way, but personally I have never experienced any of the issues you bring up.

Sure, I have been 'forced' to seek information by myself but whenever I have stumbled upon a problem the community has helped me out within hours. Most of the add-ons are pretty self explanatory, and the more complex ones usually comes with documentation - and when the documentation is lacking you can be sure someone else has had the same problem and has posted it in the add-on forums. Contacting the add-on developer directly is also an option if you have any problems, and generally you get a response within a day.

What is it you find hypocritical support wise? What marketplace items do you have problems with? What bugs are you referring to? Since you haven't posted anything (except this rant) I take it you haven't even tried to ask the community to help you out.

EDIT:
As to why you should choose concrete5 compared to other CMSs is really just a personal preference for you. Myself I find concrete5 to be very easy to extend and develop for, and _everyone_ I have showed it off to (from the average user to developer) are impressed with how easy it is to use and maintain. Discussions like these arise a few times a year and if you search in the forums you will likely find comparisons with other systems and why you should or should not use concrete5.

Can you be more specific, then maybe someone can help, as you obviously have faced a few problems:

"support on a nearly hippocrate level" What is hypocritical about the support? what support are you referring to, support for Concrete5 itself? support for add-on's?

"marketplace items without documentation" The marketplace items without documentation are probably very old as its now a requirement for approval for the marketplace to provide acceptable documentation, if the add-on is a paid add-on you are entitled to 30 days free support, which covers Bugs and functionality issues, if the add-on is free, the developer is not obliged to provide support, (many choose to provide support though) you are perfectly entitled to ask questions about add-ons in the forums, someone will help you.

Why should you use Concrete5, thats for you to decide, does it do what you want to achieve? only you can answer that.

With all CMS it takes a while to fully learn.

I felt the same way about the documentation and marketplace items for a while. However after using it for 3 months I finally understand and now I am developing my own add-ons and I love it!

I agree C5 isn't for everyone but if you sit down and learn it, it's a great tool.

I also think C5 has a lot of bugs, then later find out it was because of a mistake I had made (woops...)

ThankS for Your compassion with my struggles.
When I started with concret5 some of the issues was the pretty Urls
-as i browsed the forums i got some strange impressions,
when you browse the german site, the recommended expert site there is not even working
Well I read from Remo(the man who wrote the book) that Concrete5 is pretty easy to learn..
so i did not give up to early - until now I have set up one site
and I agree the Inside or Dashboard view feels well done
but not the standards around themes and addons...