Seriously. Every time I see someone mention hearts as quests or as grindy, alarm bells go off. I don't know which game they're fanboy of, or whether everything has to be forced within a word, even if it means using the word grind for something that is no longer grind....
Grinding is a term used in video gaming to describe the process of engaging in repetitive tasks during video games.  The most common usage is in the context of MMORPGs like Final Fantasy XI, World of Warcraft, Tibia, or Lineage  in which it is often necessary for a character to repeatedly kill AI-controlled monsters, using basically the same strategy over again to advance their character level to be able to access newer content
In other mmo's this is because virtually all quests are based on killing foes. NEWSFLASH, every single heart I've thus encountered had a no combat mechanic if I wanted. Every single heart has a handful of requirements. You can vary, you can focus on one type, or you can skip the heart for an entirely different kind of content.
Seriously, to compare a heart to quests, is like comparing a decathlon with 100m sprint. Yes sprint is part of a decathlon, but there's plenty of other fun parts in decathlon for when you're f'n bored of sprinting. Equating hearts to grind, is like equating decathlon to the sprint component.
So what I read nowadays is trolls no longer trying to shoehorn heart into the definition quest, but rather stretch "grind" to fit around hearts. You're grinding hearts because you are forced to do one of 10 different actions, which you can choose and change at will, and because throughout the entire game you can only do hundreds of variations on these 10 actions, you're grinding, because whether you feed a cow or put out fire you still use an item on an npc therefor it's grind (wtf?).
Which basically means grinding has been redefined into "enjoying varied gameplay". Newspeak at it's best.
The only thing which needs grinding in GW2 is banana and vanilla ice cream. And even then I actually blend it. Summer is hot here.