I suspect like Skype they are being careful not to claim they are a telco - so they don't get hit with all the regulation and requirements stuff that real phone companies have. At the moment they are treated like those companies that sell cheap international calling cards.
-This means that there's no support,
Buy support! C/C++/SQL/Java are free with no support, but you don't choose to only program in JCL4800 because Burroughs sold it.
- The UI design of open-source software is often terrible.
Ever seen in house or enterprise software
- There's noone to turn to with feature requests
Yes because I have Bill's cell phone # for new windows features I want
- There's no marketing for open-source software.
Depends whether you look for software on the web or in the WSJ
- You have no guarantee that your open-source software will be updated in the future
Whereas you have a guarantee that MSFT will stop selling XP
- Most business-types, don't even know that there is such a thing as open-source software
That's why they have staff. They don't know how an IP datagram gets to their web server but they still have a web site. Or possibly they don't - they will be running DecNet or SNA because you can't trust this free TCP stuff.
The P2P nature of Skype makes it difficult to identify links of bad guys (or innocent guys that happen to be in the wrong place wrong time).
Listening in on calls isn't that useful - unless you know that "the goose flies south for winter" means we attack at dawn.