On the contrary, I think that XML's bad reputation comes from the fact that it is <adverbial-particle modifies="#123">so</adverbial-particle> <adverb id="123">incredibly</adverb> <adjective>verbose</adjective>.
Also, the whole child/attribute dichotomy is a huge, huge mistake. I've been recently dealing with the XDG Menu Specification, and it contains a child/attribute design failure, one which would have been far less likely in a less-arcane format.
XML is not bad at making markup languages (and indeed, in those languages attributes make sense); it is poor at making data-transfer languages.
JSON has become popular because a lot of bad programmers saw nothing wrong with calling eval on untrusted input (before JSON.parse was available). It's still more verbose than a data transfer format should be, and people default to using unordered hashes instead of ordered key-value pairs, so it's not ideal.
The best human-readable data transfer format is probably canonical S-expressions; the best binary format would probably be ASN.1, were it not so incredibly arcane. As it is, maybe protobufs are a good binary compromise?