Paying staff in XRP is almost exactly like paying them in stock options in their own company, or paying in company scrip. That's not strange at all.

Gateways will have to buy their XRPs, except for whatever the founders give the gateways as a gift. Of course gateways will pass on this cost to their customers, but this just means that the cost of being part of the Ripple network gets paid. It could also have been done by gateways paying license fees to be part of the network, or license fees for the software, but using XRP are an interesting way to solve it.

Maybe some of the founders are hoping that XRP will become the currency of the future and hoard it - but that would mean killing their company by pricing transactions to high.