Expectations
We don’t really know if this person deserved a going away party and the same treatment as the others. Two years in a workplace isn’t that long considering that some people spend decades in a single company. On top of that, they themselves said they were not expressive enough with their coworkers.
So if you didn’t leave a real impression on your colleagues, we guess you can not expect to have an amazing party when you leave. People just forget about you and you move on, in some way you have to put the energy out there to get it back, that’s just how it works.