For example, say a group of developers have a great idea for a cryptocurrency-based service or services, but they need some kind of financial incentive in exchange for their work (everyone has to eat). So, they can clone their own coin (making however many improvements they might like along the way) and then start developing high-quality cryptocurrency services that only use their own proprietary cryptocoin (like PXC in this case, or at least as PXC was originally pitched). If their services are high quality and start to gain users, their coin will go up in value, therefore making them money. It's like a way of enabling people to issue their own stock almost, which is something pretty powerful when you think about it.
So that's why I don't have a problem with "clonecoins" like PXC or FTC or any other number of altcoins.
Oh, and with the partnering of WDC, PXC, and FTC now there is even MORE financial incentive for not only all the developers involved with these three coins, but for all the stakeholders of these coins as well. Truly exciting times.
You made my day.