I fear that you are reading more into what I said than is justified. Try taking a look at some of the other questions in that poll.
People aren't reading more into what you said than is justified. They're just questioning the accuracy / validity of what you said. You said that one in seven people in the UK are naturists:
You would probably be surprised how many of your friends are naturists, it is about 14%, or one in seven, if your friends are similar to the overall national picture.
The poll you've used to justify this claim expanded the definition naturist to include someone who has partaken in nude sunbathing or swimming. Which, as you well know, is very different to someone identifying as a naturist.
But because of the definition used, which does not reflect the general use of the term naturist in day to day life, the results of the poll included people happy to skinny dip on occasion / sunbathe topless around friends (for example) as being naturists.
If someone snogged their same sex pal at school, it doesn't make them bisexual unless they identify as such. If a poll says 'bisexuality is defined as anyone who has had sexual contact including kissing with a member of the same sex' then I would have serious reservations about the results claiming 'X% of people say they are bisexual.'
It's a flawed data set in the context of real life because occasionally not wearing clothes in specific, rare settings does not a nudist make. But I think you know that.