First things first, people make money themselves and it is their decision how and when to spend it. People love these kinds of events, especially wedding days, these days are important to everyone because usually people make a big step in their lives and it is for sure important.
To begin with, people who think spending money on special days is a waste of money, I can not say exactly what is in their mind because I personally do love these days, especially birthdays, because I love myself and those who say it is just waste of money they probably do not l themselves. This is the only thing that comes to my mind, I think they just want to earn a lot and save up it or they probably would investigate it for their future or their children such as for college or an apartment.
And the people who spend money on vacations and parties they are really know how to live, they earn money and spend when it is necessary they do not get greedy. People should take a rest from work I mean to go on vacations, to parties and then people can feel life. For instance, parties can make better teams, if people enjoy while they are spending money it is not a waste of money. As I mentioned earlier I do love parties and do not get greedy when it is time to spend it and some people spend a lot on birthdays and weddings because it is almost once in life I mean weddings, birthdays can be celebrated every year. So that is why people want to feel these moments and actually money do not play a big role if people are not greedy. What about vocation perhaps people work for it, maybe when they were kids they wanted to travel a lot and now when they have an opportunity they can do that, implement their dreams so that is why people are so different some are greedy and some are not.
To conclude, all the reasons which I gave might think it depends on people it is their money and they decide what to do with it. However people should be a little open.