Some points:
1) Shipping costs - with proper insurance, shipping adds up fairly quickly. Attending meets are free.
2) Rethink meets - Who says you have to "wait for a meet" - arrange your own. It doesn't have to be a mega meet, it could just be three or four friends in the same city on a Sunday off.
3) Fraud - Regular posters (even ones you deem helpful) can be charlatans more often than you would suspect. The largest "scams" perpetrated against this community (that I can think of) were done by respected users who were "regulars" at the time.
4) You should have something to use something - such a program should be a two way street, and you should be willing to have your own gear floating around if you want to partake of other's.
5) Damage - with a loaner program that gets sent from person to person, the person who is loaning the item will almost inevitably receive it back with scratches, dents etc (unless it's local where you can pick up and avoid shipping damage.)
So all in all, a great idea ideally. In fact, there are users who engage in this type of program all the time between close-knit groups of friends. But it is really a Utopian ideal - people are too opportunistic, and you can only know people on the internet so well.
On a small scale, with a small group of people (especially in proximity to each other) the execution becomes much simpler.