They openly and publicly backed herd immunity as the UK's initial strategy. The whole idea behind that is that you let it spread.
Well looking at this I just Googled it doesn't seem to be clear cut - according to this that was the advice that was coming their way initially although it was apparently "never policy" and they did change it.
Coronavirus: Whitty and Vallance faced 'herd immunity' backlash, emails show
Chris Whitty and Sir Patrick Vallance were alarmed by questions over the controversial concept, emails show.
www.bbc.co.uk
It just looks to me like you're trying to establish some kind of blame for a deliberate act rather than having poor strategies under consideration apparently based on advice from people who should know. It's been said many times it was never as simple as health or the economy as the two things are inextricably linked. Most governments it seems are having to walk that line.