Some travellers are more concerned that a fellow traveller has
explosives concealed on their body.

Some travellers would like to do away with the security theatre.

Travelers heading for a casino might not want their money-belt to
trigger cross-examination harassment.

Then declare that you have money on your body.

Give up your privacy in a misguided attempt to achieve privacy? Catch
22. In the US it tramples the 5th amendment.

One of the major problems with the scanner is that it's used to
discover non-safety related contraband that creates an intrusive and
irreversable industry. In the US searches are supposed to be executed
in a manner that limits the search to what they believe they will
find, not go on a fishing expedition for anything illegal. E.g. it's
not acceptible for a cop to search through someones paper documents if
they are looking for a brick of cocaine.

I'm probably getting off in the woods here, as Europe doesn't have the
same resistence to "general warrants" that the US has.