Wouldn't bother me if it was compulsory
That's fine, good on you- have a scone. The problems begin when you start inflicting your choice on others through enforcement. You are taking away the reasoned decision making from individuals perfectly capable of making up their own minds on such things. That's not good.
Amusingly I note you've already started with the "why won't you just think of the children" cobblers. Very funny.
For all I know, most of your riding is down the A1, in which case I might almost understand your desire to strap a useless piece of plastic to your head. Most of my riding is at about 10mph along routes like this...
If you're seriously suggesting I need a helmet for this, then I might very politely suggest you are barking.
Not that types of route make any difference of course, but it just illustrates the point that you simply can't inflict your choice on everyone. If compulsion does ever happen here, it would be catastrophic for cycling in the UK and I'd be joining TMN for sure in completely ignoring it.