This is stuff straight out of the pre-release hype machine that badwrongfun'd pretty much everything about earlier editions. This is stuff that says that Mearls and Co. know fun, and your ain't it. This is stuff that just plane pisses me off. To some people, some of those listed things are, in fact, fun. For a few, all of those things are fun. I think those 100 words or so would have been better spent reiterating the point of the first quote, that there is no right (or more importantly in this case, wrong) definition of fun and what matters is that the group as a whole shares a similar definition.
Instead, we've got badwrongfunism forever enshrined in the DMG, and thus, if goal are met, a whole generation of D&D players that don't waste time on unfun stuff like talking to guards, exploring dungeon coorridors or managing "real" resources.