Past events have constantly failed. SC events, boss masses, Castle Wars and Clan wars as well as many other events would have 1 or 2 people show up - chat mods/ranks. With the smaller events that were planned at a certain time, people would show up for 30 minutes and then leave. Chat mods/ranks would stay and try to get more people to turn up but nobody would. Longer events like a skill competition give more players a chance to participate because they can log in whenever they want (assuming it is within the 48hr time frame).
The smaller events need to be posted well in advance so that people know about them and the small window they have to participate. Chat mods/admins/ranks/event team that have previously tried again and again to host events with nobody showing up are going to be really reluctant for the same thing to happen again. We do try to mix things up a bit but the previous 52 weeks of the current skill competitions have been successful whereas some of the other events held in the same period of time have not
Edit: I'm all for other events but they die out too quickly and end up being a waste of time for half the people