addit;  I want to wear my Mighty Tigers footy jumper and matching socks but the cook says no.  We'll see about that...

All of them are bloody awful, including my own.

It's all a cash grabbing party, mostly to pay for the wedding itself. Insane.

The other reason for it is to make the so-called important ones feel important. This being the in-laws and the bosses. Never the actual couple.

It's a long day and a short party. None of which is enjoyable. Generally the bride and groom don't even have time to grab something to eat.

My missus said it was perfect. I loathed every minute.

In traditional Sichuan, a large portion of the guests are family of some sort. Sticking together is of vital importance to survival in China. My own wedding had 250 guests I think, but was comparatively small compared to some I've been to. People gave about 9000euros worth, and very few people opened the bottle of baijiu on the table. Our baby shower was a repeat of this procedure, though at a smaller scale.
There were no anonymous hongbao - we as the married couple handed out small hongbao to kids. My mother-in-law kept a record book of the 'gifts'. They are more like family loans, and we are expected to fork over a slightly larger sum when guests at our wedding get married themselves. Or any other life-changing event requiring lots of money. My aunt got diagnosed with cancer a while ago, and my mother-in-law got a call from her own mother, who had decided it was time to pay my aunt back.
Non-family guests are rarely expected to pay significant amounts. A while back, a colleague of mine got married. My wife chose a porcelain doll as a gift, and stated that money wasn't necessary because we are 'not family'. It may be different if you are colleagues, because company staff look upon each other as a sort of extended family.
I think it's phony that gifts don't come from the bottom of people's hearts, but there is definitely a purpose towards pooling family resources at costly times in a people's lives. Perhaps our experiences of weddings are different. Some of the guests you mentioned have no good reason to attend, so they were likely invited as a facesaving maneuver to fill seats. It's unlikely that 5 minute acquaintances are going to gift more than they'll cost in food & drink.
Opening the baijiu is considered a selfish act over here. We returned unopened botles to the dealer, and still have 2 opened bottles of that toxic crap in the cupboard over a year later. I won't drink it because I'm fond of my liver.

You didn't score an invite. You've purchased a medium quality meal that you will eat sitting at a table with some arseholes you'll never see again. The reason why there are 400 attending the wedding is that the price for sitting 10 people at a round table and feed them, is less than the hongbao these people will give as present. 

There is no such thing as a real wedding in China, the party and the actual ceremony is always disconnected, but isn't it like that in many places, e.g. if you get married in a Church in the US, haven't you been to a public office to take care of actual registration, some countries do it the real way, where the ministers actions will actually result in people being married, and the couple need not do further actions (same for a town hall wedding) 

Pefore the sham you show up to, a group of people close to the couple getting married will have been through a horrid tradition where the groom pays for his bride, they will have driven around town in a convoy of rented cars (or a fleet of crap Chinese built sedans) same shit each wedding I've been to. 

The short duration of the event makes it all meaningless to me. If someone invites guests to a party but don't intend to actually spend time with the guests, it's all just for showing off face. 

I'll participate in these events as a mans got to eat (it always the same f'ing menu though) but I will never have such an event for my wife and me. If a wedding doesn't last 16 hours then what is the point.

Me and the woman said no thanks.... Im not having a wedding filled with a million people i dont know. But having only close family would be like 40 people. So we took those 40 people to thailand for 3 nights. Only family and close friends. Still over 300 000 but at least its memorable and enjoyable.

Getting married myself in 2 weeks in Jiangxi & my wife to be has refused to do anything "traditional" for our wedding. No stupid photos of us, in fake traditional outfits, at a so-called beauty spot, with tons of other couples having the same photos taken. No wedding meal as she hates all the crap around getting hungbao & then having to make sure you give back more to people when they need it. We've already had the honeymoon in Bali & the day we get the book we'll take her parents out for dinner.  Suits me fine to do it this way especially as it's what she wanted. 

She's warned me that we might have to go & meet a few long lost aunts & uncles so I can be paraded round but we'll deal with that okay.