it's a pervasive tone, koku.
well, that may be because of that fact English is not my first language. Control tone is always difficult for me. I would be able to say the same thing with much nicer way in my native language. When I have to debate in person, I always excuse first by saying "please excuse my language because sometimes I don't have enough vocabulary to say things nicer way and it can be harsh." and this helps a lot. for example, in stead of saying "It may not be the best things to do", I used to simply say "It is bad." Usually, people wouldn't judge me from just my speech because there are other factors showing who I am.
But in this case, I understand you have to judge me just from my text because that all you have. But in the future, if you speak with someone who is not from this country and whose English is not so good, I hope you take the person's language background into consideration before you make a judgement.