I gave up on Flying Blue long ago after being very rudely patronised by a KL lounge dragon who thought she was far more important than the passengers she was supposed to be serving.
I've had the same experience many a time with the KLM dragons. The staff on reception at the Schiphol lounge have never been anything other than rude and arrogant.
As far as earning miles, it's pathetic how little you get for a flight nowadays. Unless you spend extortionate amounts on your fare you only get 25% of the miles flown, which means for a transatlantic flight you're lucky to get more than 900miles. When you then need in the region of 50,000 miles to book a reward flight, it makes it very hard to get any.