It's more of an analogy like this: You're a group leader for a group assignment due Tuesday morning. You think it's great, they're the top 1% in the class. They promise to do their sections of the topic by Monday meeting so you can work together to compile it. Monday comes around, they said they tried and didn't finish their sections. Now you're stuck all night fixing their sections and compiling it together.
That's simplified analogy, and the author would angrily call them "jokers".
Except for the bit where you're doing other schoolwork instead, I presume? Besides, I wasn't talking as much about the content of the letter as the tone--that's what I found off-putting.
That's simplified analogy, and the author would angrily call them "jokers".