Because, fundamentally, the current UK government is not interested in scientific evidence or taking advice from experts in an area (c.f. Michael Gove's famous line "people of this country have had enough of experts")
"I think the people of this country have had enough of experts with organisations with acronyms saying that they know what is best and getting it consistently wrong."
He was using the example - nearly ten years on - of how "experts" didn't predict the 2008 crash. At best, a straw man argument (which experts; were any expert advisors aware and did they endorse the extreme lending that affected the UK, etc.)
The government is on record as wanting precisely more technically qualified people to enter the civil service, and restructuring the service toward this end. Whether or not the way they intend to go about it is sensible or reasonable is another topic for debate.