[xnorswap]

Because society and culture doesn't work like that.

You can't will a culture of closing up at 4pm during GMT and 5pm during BST. That's just even more confusing.

[jampekka]

The talk was +1 offset in clocks all year around, in effect dropping DST and changing the timezone.

Also a lot of places and services have different hours during different seasons.

[xnorswap]

If you're going through the hassle of dropping DST, why not settle on BST as the permanent timezone if that's what the preference is for hours of daylight?

Asking an entire culture to change from 09:00-17:30 to 08:00-16:30 seems awkward and doomed to failure in comparison to simply landing on BST instead.