Meh, I can't fully agree with you.
They all have similarities but then too much pronunciation and grammatical differences.
Plus in the other 3 countries you mentioned (Spain, Italy and France) every goddamn movie, tv series, etca is dubbed in their own languages, so they have a pretty hard time speaking other languages (Not saying they can't, but they have to do it by themselves alone). Thankfully we have subtitles, so we can get used to and understand foreign languages a little better
But still, it's hard to speak other languages correctly without studying them, no matter how similar they are.