That is usually the case. In any major patch enough core game files are changed that existing campaigns, if you can get them to run at all, will react very strangely.
I intend to finish off my guy's career before installing the patch. With the Mod collection I have running, and the list of fixes that have been published, I am perfectly happy with the game as is and see no need to start all over again.
So to review...
Game released on time: People upset that it was unfinished and full of bugs.
Patch delayed: People upset that the patch was not released "on time".
Patch released (presumably) in working state: People upset that patch wrecks their career.
Sun comes up: People upset that it is too bright out.
JCC