The Folk Witches build their covens using Covenant rules. The Sahirs also use Covenant rules to build their Bayut al-hikma (Houses of Wisdom). Except both these traditions, unlike the Order of Hermes´s Covenants, are forbidden to take the Poverty Hook and the Wealth Boon, as their members must support themselves individually, been elegible for the Poor Flaw or the Wealthy Virtue.
So what, besides cultural factors, stops either tradition to organize itself and gain covenant-like resources, allowing its members to have all their four seasons as free time, like Magi do?
Nothing, besides cultural factors, and the negative effects of the Gift of course.
So, considering that nothing stops either a Coven or a House of Wisdom of being composed solely by ungifted hedge magicians, it´s more the cultural factors then.
Then, theoretically, it would be possible for a group of, say, ungifted Learned Magicians to take over an University as use it as their source of income, just like multiple player Covenants have done in the history of Ars Magic?
Almost anything is possible.
Plausible is another matter.
So why are the rules written that way?
I suppose it has a lot to do with the default assumption of who the characters are. The Order has built the culture where magi, usually, can live lives of leisure, supported by their covenants. The companions and grogs have to earn their living, reducing their advancement potential.
If, suddently, we have companions who, because they are unGifted hedge practitioners, have their own covenants where they have the magi's seats, a lot of the dynamics change.
Hence, this makes a lot of sense to me. ArM is a game about Hermetic covenants, and the rules are written to make that the preferable setting. If you want to play a game about a hedge covenant instead, you have to make the adjustments yourself.
But then, we were always sceptic when Hedge Magic first came for 4ed. It sort of changed the theme of the game.
True. The real reason Covenants have acess to income and Magi are barred from the Poor and Wealthy Flaw/Virtue while Hedge Mages are the oposite, is to one more thing making Hermetic magi better than their hedge counterparts.
Afterall, the true basis of an Covenant´s income are its subordinates, it´s grogs and covenfolks. None whom have acess to Parma Magic and, therefore are afected by the magi´s gift.
In truth, the more logical option would be for Magi to have to spend two seasons per year working to ensure their Covenant is well managed and has the income it needs to maintain itself. But then it would not be Ars Magica.
Depending on the game, the early adventures might be exactly that. Setting up deals with local mundane or supernatural potentates to secure passive income flows and to recruit a head of the guards and a Steward, who will take care of the boring daily things on behalf of the magi.
It could be, but there is something not quite satisfactory with taking up half the time of one's principal player character without actually playing it out in stories ...
... which I suppose is why many sagas make really slow progress, and many players get sick of starting Spring covenants.
Well, hermetic magic is quite flexible that you can easily imagine how the magi systematically ended up on top of a money-making scheme funding their lab. Touch of Midas, Aura of Rightful Autority, the bountiful feast, etc. Most hedge wizards don't have the tools to rapidly generate wealth or influence a group to gather that wealth on their behalf.
There is also the Order itself to consider, especially on how they handle Hedge Mages that seem to be gathering power or touching on the rules that they enforce.