Text based protocols may seem easy but often leads to unnecessary complexities. For the sake of human readability, protocols that start out simple at first eventually gets bloated and overly complex. Just look at the WS-* protocol stack if you want an example. And not to mention characters being garbled because the creator of some homepages didn’t bother to define the charset.

While we have problems like endianness in binary communications, text encoding is no simpler and can also be ambiguous which causes hidden headaches and sometimes nasty security holes too. I guess you must prefer something which seems easy at first but is hard to validate until runtime. Script kiddie mentality.

The reality is that XMPP is already there, it is not bad and better than other existing ones.

I have deep experience about XMPP and Google Protocol Buffer.