I have a feeling it is two teenagers are trying to get you to believe this things which you cannot prove.
1-) Every western European country "forces" its students to learn a foreign language.
When you go far enough back it was Latin, then it was German and after WWII it is English as first language.
2) English is taught as England is a European country.
3) There are many more diallects in United Kingdom than there are in USA.
4) Foreign languages are very seldom taught by a native speaker in the schools.
It is taought by a person who learned the language as a foreigner and often speak it with an accent.
5) It depends on where you come from how your accent is. The Danes speaks English with very little accent. The Finns have heave accent in every foreign language they speak.
"The thinker thinks" come out like this from a Swede "Te tinker tinks" and from a German !Se sinker sinks"
6) Whatever languages you learn your native language will be the one giving you an accent. If French is their second language they will have a Finnish accent in their French and not a French accent in their English
Stop listening to what these two girls tell you to get your attention and pity.
They seem to be pulling your leg completely or they are telling you stories that are half true and with no real knowledge behind it.
Stop listening to them - get information and tell them off. And stop feeding them with Finnish musich or whatever. They now live in ISA - the should speak Englsih with whatever accent.