No, it is relevant because people will stop using Ripple the more times they have to pay for other people.
As I said, we're not relying on community/social credit. We're promoting Ripple as a payment system based on gateways. The social credit system will always be there should people be ready to use it. I agree that it's difficult to use safely right now, hard to understand, and so on. Much better tools will be needed, and even then it may never catch on. I genuinely believe that one day it will be Ripple's killer app and will transform the way people think about money and finance. But we're not relying on it.
In any event, among people using the same currency, the path will almost always be either:
Payer -> Gateway -> Recipient
or
Payer -> Payer's Gateway -> Middle -> Recipient's Gateway -> Recipient
Where the "middle" will typically be someone who holds IOUs from the recipient's gateway and accepts IOUs from the payer's gateway. Both the payer and the recipient are only necessarily trusting one gateway. You won't have to do more than that to use the system to make and accept payments.
The more hops there are, the more likely this is going to happen.
The number of hops has no effect on the number of people who owe you money. There's just no connection at all.