Probably because it is not really clear what actually the consequences will be.
I have read quite contradicting information, so I feel pretty much confused what to expect.

Allegedly, there is a 'guillotine clause' in the bilateral treaties, saying that in case of a 'no', it will take only 6 months the treaties to expire.

Another source was claiming, that this 'guillotine clause' would not come into place/would be reversed.

Anyway, I am a Swiss in the UK, without any resident permit, just here because the bilateral treaties made this possible, so I am actually pretty nervous about the outcome.
Don't want to be kicked out of the country...