Achievements: Earned or Entitled?

Often you'll come across the following type of comments in a discussion about a particular game's achievements/trophies (I'm primarily a 360 gamer, so forgive me if/when I fail to mention trophies when I mention achievements):

Gamer A: “WHAT?!? Beat the game on the hardest difficulty without dying (or any other difficult feat)? What kind of stupid achievement is THAT? How do they expect me to earn that? That's fucking STUPID! Most people won't get that! Why would they make an achievement that's so hard to unlock?"

Gamer B: “Well, shouldn't the people who do that get rewarded for it? I mean, if someone develops the skills/takes the time to do it, why shouldn't they be rewarded? They did something awesome! They actually achieved something.”