then this would be an infinitely scalable solution...

I think you've missed the point that's been made above & so I'll try to make it with a bit less subtlety:

Infinitely scaling the XP system is like infinitely scaling everyone's ego.

One of the things I really like about the metaphor of the Monastery is the aspect of Humility that it infers.

A Saint, above all, should be humble.

If you've contributed to the site to the extent that you've achieved the rank of Saint - you have been honored for your efforts with the highest award available. Your ego is served, and you can accept it gracefully & continue to do what you've done all along - contribute to the community.

In the USA we have a thing called the Congressional Medal of Honor. If you do something conspicuously worthy there's a possibility that you might be honored with it. It's the highest award there is. There doesn't need to be multiple levels because Jane saved a bus full of children from certain doom, but Mary saved two. Nor is the honor conveyed lessened because of this.

Why do you need a constant 'reward' for participating? I find the concept that 'XP-Whoring' could continue 'infinitely' to be pretty scary.

I think the system as it stands is imperfect, but has the lasting benefit that it Works! And what I mean by that is - if you're lured into the community by the fame & notariety of titles - you'll be bored & discouraged long before you become a Saint. Persons of this ilk are more likely to lose interest & go away. If OTOH your interest is based on the community - both in how it can help you and how you can contribute to it, then "levelling" is just a pleasant happenstance.

I have personally always been more impressed by Saints who post only when they have something they find important to contribute & thus have very few posts. Who would argue that Erudil's contributions are of little value? Only a fool.