No reward - No event mentality

Omnitec raises an interesting problem in a new Tip.it article. The problem is about players not willing to participate in in-game Tip.it events unless some kind of monetary/status reward is at stake.

Quite honestly I haven't experienced this problem myself. The events I participated in were organized by much smaller communities (like Canting Away festivals, Runetower or Runewise events). While there were a few activities with rewards attached, I don't think there was a single person who would come to those events because of the rewards. Quite on contrary, people were willing to sacrifice their experience and money in order to make it fun for everybody.

So, is there indeed a problem? Is that the case where size of the community is a deciding factor?
Does the problem appear in clans too or only on really big sites?