Bit of a strawman argument you've made there.
It's the UK government that have made the decision.
https://www.bbc.co.uk/news/health-57021738
"The risk of a clot is roughly one in 100,000 for people in their 40s, but rises to one in 60,000 for people in their 30s. Two in a million people in their 40s died rising to four per million people in their 30s.
At the same time, the risks of developing severe Covid, if you catch the virus, fall in younger age groups."
I'll wait for you to back down suggesting I'm spouting anti vaxxer propaganda.
Edit: Just to spell it out for you, someone has made the decision that it is is riskier in the current covid situation for me, a healthy 33 year old, to take the AZ vaccine, than it would be the risk of a) catching covid, b) then have a severe illness from it. So they've been giving below 40s an alternative.