All sales websites should be running bitcoind or similar and not be dependant on a remote service.
Personally, I think that is bad advice. Every small shop owner that decides to accept bitcoin should NOT be forced to run a full bitcoind node on their server. If that were the case bitcoin would fail. Bitcoin needs 3rd parties and lite clients to make the process easier for integration. Blockchain.info API offers an amazing service absolutely free. Yes it does go down from time to time, but the trade off is well worth it. I can register a website and hosting and start accepting bitcoin on my new website using blockchain.info's API in a few hours. No time needed to download the blockchain and no extra bloat to my servers bandwidth from having to run bitcoind.
As for the OP's question, sounds like bc.info is having some tech difficulties with the payment forwarding. The receive payments API should come back shortly.
For there to be a trade you've got to do more than give something up, what do other solutions provide that's worth giving up a customer every now and then? From a business perspective you can't recover from your "free" payment network going down. The system was having problems just as the user was setting up... That's not from time to time.
How does 3rd parties and lite clients to make anything easier? Maintaining a connection to a single remote site over maintaining an application, it's not really much of a bargain.
There are simple solutions to the issues you've pointed out regarding the negatives of running bitcoind. However there are not any solutions to working with a 3rd party's free service.