Something to do with farmers, harvest and maximising daylight hours? Just a guess, but sounds reasonable (to me at least).
Does it though?
The number of daylight hours is exactly the same.
And farmers like to tell everyone they’ve been up since before dawn whatever time of year it is, why does it matter, to someone who historically is self employed and their own boss, whether the alarm clock says 5am or 6am or 7am when they wake up? Is it so that their employees can’t claim it’s unsociable hours and demand more money?
Even the argument for moving to GMT+1 all year round only seems rooted in a bit of collective laziness, we could all individually enjoy the same benefits just by getting up at 6am rather than 7am and going to bed earlier. But ….. we don’t.