There are ways around this. Most European airports have baggage lockers. You can put a lot of your heavy stuff in the locker, check in to get your boarding pass where they weigh your carry-on, then reclaim your stuff from the locker. I do it all the time. It may cost me 10 minutes at the baggage lockers but saves me 30-45 minutes at baggage claim upon arrival.

I have my carry-on weighed about 50% of the time at check in but never at the gate as you board.