"Real world" IPOs work in a similar fashion. Just because you wanted 200 shares, doesn't mean you get them - you bid for them and find out the day or so before the IPO whether or not you get your full allotment.
It's not random, however, there are some set rules.
And some rules are better than others.
These were stupid, for the reason I explained.
First come first served (with some cap) might have been much better.
If you write a rule assuming something happens, and people manage to exploit it in their favour, you've failed. This is what happened here.
No big deal, but refusing to admit that this rule was deeply flawed is hugely delusional.