Many people like to celebrate these Chassidish events because they’re enjoyable. It’s a shame that they try to disguise it as a religious observance. It’s just another piece of what I like to call “Feel-good Judaism”, where people just pick parts of various Mesorahs, whatever gives them a warm fuzzy feeling.
In most cases, people don’t really have any religious context for it.
Here is another example:
In my community, a number of people switched from davening on Shabbos morning at a minyan which is at a usual time, in order to go to a late minyan (not starting until 10). When I asked a friend “what about the halachos of zman Krias Shema and zman tefillah?” his response was that Chassidus has minhagim of different zmanim, so it’s ok. This person is not a chassid – he doesn’t keep any other chassidish minhagim. He just picks this because it’s easy for him.
Judaism isn’t about feeling good. Yes, doing mitzvos should make you happy, but it doesn’t always. It’s about doing what Hashem wants from us, however it makes us feel.