What are reasons that prevent smokers from switching to e-cigarettes?

Instead of inhaling thousands of different chemicals from burning tobacco (many of them being very harmful), there are only very few chemicals involved in smoking e-cigarettes.

Inhaling nicotine from e-cigarettes results in (almost) the same kind of satisfaction, unlike gum and patches.

There might be some harm involved, but compared to the daily exposure of thousands of chemicals, it’s highly unlikely that there is greater harm.

E-cigarettes also save a lot money.

I’m not a smoker, but I’m still curious: Why not?