My humble take on the Chinese New Year/Lunar New Year debate
TLDR: it's complicated. There are good and bad arguments on both sides. I'm writing as a Chinese person who knows very little about other Asian cultures, so while I only write things I believe is accurate this post will have a focus on China.
Arguments for Chinese New Year
The new year festival celebrated by Chinese people is at a different time every year on the Gregorian calendar. This is because the festival comes from another calendar. That calendar is a mix of lunar and solar calendars, so calling it Lunar New Year is inaccurate.
If it's a Chinese person discussing the new year festival as it is celebrated in China with all the customs and rituals then they have every right to say Chinese New Year.
Chinese diaspora communities may want to use this term to emphasize their cultural heritage.
Country X's new year traditions historically comes from China, if they want their own new year they should get their own calendar! -> this ignores the fact that these festivals in other cultures have evolved to be quite different from Chinese celebrations. We don't get to own something forever just because historically it originated from a place we currently call China (I say this cuz I doubt the concept even existed back then).
It's cultural appropriation if you don't recognise the TRUE origin of the cultural practice! -> Oh come off it. We call Er'hu a traditional Chinese instrument when it was originally from central Asia, no one has a problem with that.
Countries X Y and Z were our ć±ćœ (Shu Guo, I think the translation is 'vassal state') which was why they called it Chinese New Year. Their fault they were inferior! -> I kid you not this is actually a sentiment I often see on mandarin media, and of course it's utter bs.
Other cultures have stolen our festivals and registered their new year traditions as a cultural heritage with the UN first and now when people say LNY all they think of is e.g. Korean new year so we are being appropriately protective!! -> this fundamentally misunderstands how cultural heritage works. A country getting their cultural heritage X recognised doesn't mean they have sole ownership over every tradition that bears the same name, and the UN has no authority over this matter. And no people don't think 'LNY' is exclusively Korean.
Arguments for Lunar New Year
I'm talking about the festival as it is celebrated in culture/country X, which is not China, so it's not Chinese New Year.
I'm trying to distance my culture from an emerging superpower which has historically been quite famous as an oppressor of my people/exerted dominance over my country.
I'm trying to emphasize the unique traditions we have that is different from the Chinese culture.
I just don't want my festival be associated with China.
To be inclusive you have to say LNY, otherwise you're ignoring all the other countries/cultures -> but when people use LNY they do tend to include Chinese new year traditions, which are not based on a lunar calendar, and if I understand correctly LNY is inaccurate for other countries/cultures whose new year is historically derived from the Chinese one. Other cultures/countries may have reasons to accept LNY over CNY (for example the very good reasons above), but many Chinese people want it to be accurate.
You're being a hopeless nationalist/imperialist if you think it should be called CNY -> I used to think like this because I thought everyone arguing for CNY were using the BAD arguments (trust me a lot of people use a lot of bad arguments). But as discussed, there are genuinely good reasons to advocate for CNY.
Basically, the situation is this. We need an umbrella term for all these traditions. However, as an umbrella term, CNY is too emphatic on the Chinese heritage, and LNY is inaccurate.
What about we have a look at how the new year is referred to in every language whose users typically celebrate the festival? In Chinese then literal translation is the Spring Festival. From what I've heard it's similar in Vietnam. Idk about other countries or cultures, but if the 'Spring' thing turns out to be a common thread indeed maybe that's what we should do? Just Spring Festival?