Being Dutch, I agree with them. My English is a lot better than my German, even though I live about 10 miles from the German border. It helps that a lot of TV shows are in English and English is the language of the internet. On the other hand, I've also heard that Dutch is a very hard language...
On pronunciation, there's a great poem on the internet that starts with this:
Dearest creature in creation,
Study English pronunciation.
I will teach you in my verse
Sounds like corpse, corps, horse, and worse.
I will keep you, Suzy, busy,
Make your head with heat grow dizzy.
Tear in eye, your dress will tear.
So shall I! Oh hear my prayer.