And if it did take 800 votes, that's more than two years. I don't think someone's going to faithfully vote for two years straight just for one month of VIP. So putting it in at all wouldn't be all that helpful. The most someone could get overall in a short period of time is simple things like ingots or such, which aren't all that helpful in the long run when you could get more of them just by mining for a single day.
Secondly, I believe that by "supporting" he means that it actually helps the server because they use the money given to them to actually pay off server debts, buy new things for the server, etc. Whereas voting only from what I know keeps the server up in the list of popular servers on PMC, so donating and voting are not supporting the server in the same way to put points rewards in each one.