True, but the issue isn't so much the verifiability as that some people take things on face value because Wikipedia articles are dynamic, and as they can be changed at any time, some people are bound to get incorrect information.
Example: Yesterday I looked up Gerard Butler (not sure how I got there, mostly clicking through) and found out that he was the son of his father (the real one) and King Leonidas. Now my understanding of biology entails a woman being involved (well ... generally speaking) so I did not fall for it, and I doubt anyone would. Take however articles about things that people do not know about, cold fusion for instance, and there is ample chance for someone to distort how effective it might be. Reading up on it the other day I was surprised that according to wikipedia they appeared to making headway.
The issue there would be that it could be factually wrong, OR it could have been worded wrong, so by implication. Reading the links that verify it were beyond my immediate interest and left it at that.
The casual reader is unlikely to use Wikipedia as a starting point on casual topics, but as a source. It is unlikely that many will fall and history will be re-written ... actually, there is a chance of that...
But you are quite right. Truth is not what wikipedia is about, its a quick source of information. The caveat has to be that it may be a poor source for some topics at some times, and an excellent for others (or the same) at other times.