I love the optimism but that's not what happens when IT services get outsourced to tender. The process is almost exactly the same. MOD, NHS, Schools, Councils, you name it.
Firstly, tender bids have prerequisites on their bidders. You need to be on the "preferred provider" list. Security checked. Higher-level security vetted. DBS. Etc. This is the sort of stuff that stops small local companies getting in.
That means lack of competition and that means —as well as the price being 10-20× that in the natural market— that vendors have all the power when it comes to detail negotiation. They spec out the cheapest, easiest option for them, not what's best for the customer.
If the customer (a lowly NHS trust or CCG) turns around and says "no Linux, no sale" they'll offer a [much] higher price for the open system, or just say no. All three vendors that responded do the same. Windows remains.
This will only be solved when CCGs start working together and start in-housing some of this development work. But it's still apparently better to spunk £50M over HP for some dodgy tablets that don't work than hiring a team of (eg) 40 developers for 10 years. That sort of developer time, working on site, you could actually start to fix things.
But now I'm being optimistic. A Tory government in-house something when their mates own shares in HP? Not likely.