So your argument against a flexible format is because it requires a hardfork to change existing fields?
You've been scammed. "flextrans" _ISNT FLEXIBLE_. Bitcoin can add fields fine, even without a hardfork: thats exactly what segwit does, for example-- it adds witness fields to every transaction!
Flextrans is less flexible and less efficient, doesn't completely fix malleability, and incorporates security error prone design features (like non-canonical encodings). The only thing 'flexible' about is is the ethics of the person who gave it a deceptive name.
why don't we switch the www to hard coded binary formats,
The web is not a global consensus flooding network, among other reasons. And in most fields XML is considered to be a massive failure. Talking about making Bitcoin transactions in the network XML (with bonus proprietary binary packing method like EBML) would have been a great april first joke if classic hadn't poe's lawed this.
Also, classic is now a Bcash client... so I think this thread might now be more ontopic for the altcoins subforum.