I'm amazed at how many people have their heads in the sand in this thread. Grind is not in the mind. It's a real issue. Specifically, it's one possible outcome from any given encounter. The way I see it, there's only a handful of possible outcomes for any given combat encounter.
1) The PCs win, quickly and efficiently, but are challenged. This is the ideal outcome, yielding maximum "fun".
2) The PCs win, but aren't challenged, and simply flatten the enemy opposition. This may or may not be a good thing, and may or may not be "fun".
3) The PCs win, but it takes a very long time. "Very long time" is subjective: for some people, an hour is too long, while three hours might be perfectly acceptable for somebody else. "Too long" is like porn: you know it when you see it, but it's otherwise hard to define. This is what we call "grind" and is generally an undesirable outcome.
4) TPK. Almost always a bad thing... almost always, but not always.
5) The PCs retreat, or the battle is otherwise ended prematurely due to plot reasons.
Here's the real secret behind "grind": encounter design is a skill. Those who are naturally skilled in encounter design, or who quickly picked up the necessary skills, tend to forget this. I was not one of those people, and my earliest Dungeons and Dragons 4e experiences were chock full of grind. My first ever dungeon crawl that I DMed for my friends was a whopping seven hour marathon. We still had fun (mostly because of the novelty of it all), but there was definitely tons of grind, and I knew I needed to take countermeasures to reduce it.
The very fact that we need to take countermeasures suggests that grind does exist, that it is a very real phenomenon, and that those of us struggling with it don't just have an attitude problem. People also need to consider that, in MM1 and the original Dungeon Master's Guide, there were some very real problems with the math. For those of you that honestly believe that "grind is in the mind," I dare you to make a grindless encounter with 3+ Wraiths, with their lovely insubstantial, regeneration and weaken combo intact. Or, hell, how about an encounter with an as-written Dracolich?
Encounter design is a skill, and a very big part of that skill is knowing which monsters to avoid using. Some are so unbelievably bad and grindy (I'm looking at you, Dracolich) that they almost feel like pit-traps. Novice DMs can blunder right into them, if they're not careful. Other aspects involve knowing how to use terrain and fluff to make things more dynamic. WotC's published adventures and encounters are notoriously underwhelming, so novice DMs don't have very many good examples to go on. Therefore, they come to boards like these for advice... and I for one find it disheartening when they're greeted with a lot of: "There's no such thing as grind, it's all in your head, it's your attitude problem."
The very fact that we're discussing this, that Stalker0 saw fit to create his great guide to anti-grind, suggests that this is a real thing that people actually struggle with. For those of you that don't have and have never had problems with grind, great. Congratulations. I'm glad the game has gone so smoothly for you. But please, please, please stop belittling those who do have problems with grind. For some of us, it's a very real problem, one we have to learn how to avoid.