Linda,the problem is that painting wallpaper is too permanent. While you can have problems with the gaps or doubling at the sheet edges, these can be overcome. What does stay is that the glue on wallpaper is made to come off. If you paint, particularly with oil based paint or primer, you seal the glue in and make it very difficult to remove the paper. At the same time, any water that gets behind the paper can cause a later release of the paper with a subsequent mess.
Stripping wallpaper is not that hard, particularly if your walls were primed and sealed before the paper was applied, as they should have been. If you had painted wall and then papered these, you should have no problem at all with paper removal. The “secrets” of the removal process are to use HOT water and vinegar or DIF with a tool called a paper tiger.
One other thing that seems to be missed by people having trouble with wallpaper removal is that paper with vinyl, metal foil, flocking and a few other treatments will not let water get behind the paper easily, even after using the paper tiger. The answer to this problem is so easy that even a 4 year old can do it and that’s to remove the vinyl, foil or whatever. The kids seem to be pretty good at finding one little loose spot which they grab and soon remove the whole big piece of wallpaper. If you are trying to remove the paper, they really enjoy doing this.
Henry in MI