As for what Koreans think of Yulia, I think it's safe to say that they have no grudges against her. Many people had her vs. Yuna at Sochi, but eventually she was not part of the controversial result and (technically) had nothing to do with Yuna's placement, so I think they don't hate her or anything.
But, even with the surprisingly pretty big audience at 4CC this year, figure skating is not as popular as people think. Everyone (yes EVERYONE) knows Yuna, from elders to kids, etc. But even with all that Yuna had done for Korean figure skating during her career, South Korea's interest for the sport has only grown a little bit. As soon as Yuna retired, many people in South Korea started to forget about figure skating. Even though the country FINALLY has skaters who have the content and remarkable level in the sport - So Youn Park and Da Bin Choi - So Youn has a big consistency problem, which sets many people off, while Da Bin is just not well-known yet. So the country is not seeing the success that Yuna had with their current skaters.
So the reason I said all of that (sorry for such a long paragraph!) is because it most likely means that South Korea knows little about other countries' skaters (since they need the spark of interest from their skaters). They knew Yulia because of Sochi, but they most likely do not know that she struggled a lot last season and is a bit different now from Sochi. However, I am not referring to the country as a whole. There are still some FS followers in South Korea.
Imagining that someone from Korea stumbles to a Yulia video of this season, I think they will most likely not be critical or insulting to her skating, at least if they find out why she's struggling and understand. Adelina would be a different story though, and don't even get me started on what they think of her...