How many folks are running around using WP, Meego, and Symbian?
And out of those numbers in each of those OS's...how many of those folks are knowledgeable enough to fix their variant of Skype?
And that is saying that the past "fixes" to get Skype functional on those specific OS's is the same kind of fixable problem as the past issues...
Which in point of fact...they aren't.
Skype has moved deliberately so far away from being "fixable" for Meego, WP, and Symbian it is now an impossibility to fix.
It is a combination of dropping of support for old os's and increased expectation from aging versions that are heading out the door..marked for discontinuation...
Where once upon a time it was fixable for the OS's in question...
It isn't any longer.
Also to add to the issue is that..
Unlike other services such as Telegram, which has a much more open policy and IF there are folks in said community that can juggle work -arounds for it...then it can be kept going for a while..on said OS's...
But more closed progs such as whatsapp , Facebook, Skype... etc...
When they make changes they are not easily worked around to get them to function again..
And to make the issue worse still..
Said progs like Skype, Whatsapp , and Facebook on a consistently regular basis change their progs so significantly ...in some cases multiple times in a year...effectively making any fix temporary ...
So.. whoever does work on "fixes" is doing so perpetually...
In essence you need a couple people working on a "fix", or a small team to do it and keep maintenance of said programs..

It just isn't feasible.
The n900 was probably and compared to the other mentioned devices.. Has still greater numbers of savvy users, power users, and cunning folks that can " fix" lots of issues...but even still...
See any running Facebook, or Whatsapp app for the n900?
Skype is so much more difficult to attempt to fix.