Ah but I didn't say there were foreign did I?
No: you just made a general statement about it being in your view 'a bit unprofessional' for a formal announcement to be made by cabin crew who pronounce their 'th's as 'f's and their 'h's as silent 'h's.
I am surprised that you seem to fail to realise the implications of what you say with respect to crews whose native language is not British English and who may have a different pronunciation of English from your own personal expectations.