Why would you want them to add altcoins as well?
Bitcoin is the safest and best option for any service, site or merchants.
Peercoins are a pretty decent choice as an alternative, IMO. Nothing wrong with Bitcoins, but why just limit the choice to one cryptocurrency only?
Why would they add altcoins if they already have Bitcoin.
Bitcoin is getting more and more support from around the world.
Serious companies and organisations won't choose for altcoins.