I have noticed a trend of other nationalities upvoting their own. The South Africans steemians seem to have a pretty tight group and the Aceh community upvotes each other, though I haven't really noticed any of the posts you mentioned. On one hand I don't see a problem trying to help grow the following of steemit in your native country, however I also feel like the quality of your post should matter, not just where you are from.
A crap post is a crap post in any language and shouldn't be rewarded based solely on geography. The same goes for quality content as well, a well written post will get its due, be it in English, Chinese, or whatever.