Flamestrike
Legend
You skipped past the fact that wotc's own hard cover adventures are not built with a six to eight encounter grind fest either.
Yes they are.
Not every adventuring day has to feature 6-8 encounters. No-one is saying they do. Many will feature far less (and a few will feature far more).
I own every published adventure, and literally every single one of them contains multiple large dungeon areas, with up to a dozen or more encounters each level or each dungeon. In addition to those large dungeon areas, there are solo encounters, smaller mini dungeons with 3-4 encounters and so forth.
HotDQ, has you forced into an overnight siege (single AD), then raid a Bandit camp (single AD) and so forth.
It's up to the individual DM as to how they choose to police the Adventuring day. You dont have to sit there and let players game the 5 minute Work Day, any more than you have to sit there and watch as they cart around a bag of rats.
Nothing stopping a DM from imposing a Doom Clock, simply saying 'Nope', applying any one of the several Rest variants the game provides (or using his own), throwing a 'random' encounter at the party till they switch on, having an out of game chat with the players, or whatever works.