I've been in countries were the sun sets at 9-9.30pm and it really is not a comfortable feeling to be walking around at that time of night with the sun still shining in some weird twilight.
Are you serious??? In Belgium, where I grew up, the sun sets after 10pm in the middle of summer and I really, really miss that. Long twilights too and I find the light absolutely gorgeous. It's such a different lifestyle when you still have natural light close to midnight. The place really comes alive at night that time of the year. Then of course you have the downside which is that in winter you only get sunlight from about 9.30am till 4pm, so you can have days where you just don't see any natural light if you work inside.
And I agree that the going to bed when it's still light is only a mindset. I grew up accepting that that is just what you do during summer. Just like I had to get up and go to school in the pitch dark in winter.
The main reason why I let my daughter go to bed later in summer is that we don't have aircon and it would be impossible to get to sleep before sunset. She copes...