This is partly true.
The making of laws can be initiated by public pressure or a majority view, but in all cases the law must be weighed up to ensure they don't conflict with other laws, elements of the constitution, impinge on things like others freedom of expression or belief without good reason, and so on and so forth. There is also the consideration of whether a law is actually enforceable and whether or not it's "good law".
Nudists are very much a minority in this country, however when the Sexual Offences Act 2003 was set out specific consideration was given to their freedom of expression. This is why nudity in and of itself is not a crime, but has to have an aggravating factor in order to cross the line into a criminal act.
There is also the fact that a govt mandating a certain level of clothing is likely to be unenforceable and full of holes (I set some of this out earlier in the thread). It would be bad law, regardless of whether or not it had public backing in a referendum.