Why do people have a mistrust of artificial sweeteners?

I’ve read comments on anti-splenda sites that claim splenda causes all sorts of health issues(correlation does not imply causation). I’m sure I could find the same sorts of comments about aspartame and saccharin as well.

The one issue they claim that stands out the most and is the only truthful claim, is an allergic reaction. The people go on and on about how it should be banned and that it isn’t safe for human consumption. Seriously? What about peanut butter? It is deadly to the right people. Should we ban peanut butter?

I argue that while artificial sweeteners may not be the best thing to use, they are far from the poison some of these nut jobs claim them to be.