which are... none? I don't mean to be cynical sorry, but social benefits are US citizen subject that warrant such high taxes while living abroad?

We live in NL and definitely don't get/need any benefits from the US.

These may be true, but yet other countries don't do this.

I once worked with an American guy who served 5 years in the French Foreign Legion. This poor guy played hell when he returned to the US after an almost 5.5 year absence. The Legion gave him a new name during his service and French citizenship upon completion of his tour, and when he returned to the US, he said they treated him like a pariah. The IRS audited him, yet did not assess him any levies. It was a nightmare for him that took over 6 months to sort out--with help from a tax attorney.

Consular services in many countries are a joke, even for citizens, with bored bureaucrats taking out their frustrations on people who frequently have no other recourse. The state department is nothing like what is depicted in movies and on TV.