Where has this notion that the government want as many people to be infected come from? Literally the first piece of advice earlier this week from the PM was to stay at home if you have even the mildest of symptoms.
People will hear what they want to hear. The idea of herd immunity has been mentioned because it's a thing, not because it's being pursued as policy. Can anyone provide a link to a government member saying specifically that they want 40m people to become infected? I'll save you the time, you won't be able to find one.
The banning of public gatherings isn't a u turn either, it's always been planned but the policy was to not do it too early.
I really do think some people need to get their news from places other than Twitter and Facebook.