How *could* we have resisted? What were our options?
This is not just a theorethical complaint. I think there were in practice many different things you (in the plural sense) could have done that could have worked adequately. Too many things to list here, you can look up how other people protested in the past.As for the many, many things which could have worked in your opinion, people have been resisting the introduction of such laws for years. A common, and correct, refrain on HN is that the people resisting have to win every battle; the people trying to introduce such legislation only need to win one.
To some extent this is true I suppose, but these laws are not (yet) irreversible. The people introducing them have to keep winning for them to remain on the books.
It's hardly the stupidest thing British people have voted for in the last two decades, probably not even in the top 5.
However, I don't doubt that a lot of the UK would vote for such a law as most people have a knee-jerk reaction to "won't anyone think of the children?".