yea what Ed said about Unity.
I say it's expensive because a client is not going to want you to make a game for them that says "made with unity" they are going to want it branded with their own splash logo.. and if you want a game for iOS and Android (pretty standard request these days) you're looking at $4500 to own a pro license or at least a 12 month commitment at $225 a month.. to lease the pro license.. so yea unity is not cheap for professionals.. it's fine for indies doing their own thing and don't mind some branding.. and you really can't expect a client to be billed an extra $4500 for software.. unless you've found a very very nice client.. heh
Now to C2.. yes this is the issue.. and honestly there is a problem that goes into software development in general.. tutorials for example.. are snapshots in time.. they tell you how to do something at THAT time.. but because everything is changing.. XDK.. phonegap.. CJS (now I/O).. C2.. tutorials themselves have to be somewhat living things.. and this can be a lot of work..
That said any engine has the same problem.. try googling tutorials or whatever on youtube for unity tutorials.. some go waaaay back to versions of unity where the interface is considerably different and methods change.. I don't expect C2 to solve this problem..
but what they can do is "pick a plot line!" to quote Fear from the movie "Inside Out". There are no certainties in life (like C2 ultimately abandoning CocoonJS for good reasons) but if C2 could declare the "official" publishing path(s) for various platforms then developers could team up and focus their energy to help each other work through things.. but right now we have a 3 way split.. XDK (my choice so far), Cocoon IO and PhoneGap.. and I guess Adobe PhoneGap Services (whatever it's called) so actually 4 routes..
This means that now when you ask for help with your platform a good number of people won't even be able to help other than "use what i'm using..." which is tiring after you've already put energy into one that pretty much does the exact same thing.. just at that moment unsuccessfully but will likely work again at some undetermined point.. heh.
I'm willing to go with whatever platform works best. I just feel like C2 needs to take ownership of this issue and offer its community a real solution. For now I'm going to stick with XDK as long as I can till perhaps Ed's tutorials are in place because i followed the other one and it failed with a bunch of plugin errors which pretty much was enough for me.. seeing plugin drama was the last thing I needed to see for a first impression of Cocoon IO. However i hear it's APK's are smaller than crosswalk so I'm very interested in that.