I'll accept the hills, but..... surely it's possible to have a bike as reliable as a Dutch bike with gearing to suit hills? Not mountains, just hills.
The weather, I think, is more psychological.
I used to be one of those who'd avoid cold and wet like the plague. Then I realised it wasn't so bad. Then it became less bad and just a different aspect to cycling. With the right mindset, it can be overcome.
One thing about the Dutch, is that they are very practical. They'll have very practical outerwear to get to the pub in winter, but once inside, they'll drop the outerwear to display the designer gear.
The fashion displays on Geordie Shore (especially in winter!) always used to raise incredulous cries here!
And.....by your own admission, utility cycling used to be more popular. Perhaps the weather has changed, but the topography hasn't.