Welsh – I would say no in answer to your question.
There are very strict rules in the language, and it is quite complicated, not least for its mutations (an equivalent example being the h at the beginning of the word head in the sentence: “Your head is too large” changes to a different letter when the posessive changes to my… Your head = Eich pen. My head = Fy mhen.).
It is also written far more formally than it is spoken. The equivalent of speaking the phrase: “I don’t like this” and then writing “One does not like this”...
I don’t like that (spoken) = D’wi ddim yn hoffi hwn. (written) = Sain hoffi hwn.
However, whilst it is agreed that written Welsh should be formal, it doesn’t spark the controversy nor disagreement that we see here over the English language. I think there is an element that Welsh speakers are glad that it is being used at all, and the older generations of Welsh people are often not that educated in their written Welsh in terms of being able to write it “correctly”. Also, Welsh is affected greatly by English words, and there is an accepted amount of Wenglish used, even on formal Welsh tv programmes, where an English word is used when there is no exisiting Welsh word, but made to sound Welsh. It’s quite amusing really.