Plus, it gives another glimpse into Gumball's hypocritical self righteousness. Like "The Potato," only with bigger consequences. Gumball can make a point, and he'll usually stick up for it until it's inconvenient for himself. This is the first time I really saw him sticking to that until just the end. Like in "The Sweaters" where Gumball refuses to give in to fighting the Richwood students, but then willfully gives in when Penny says it's brave of him to stand up for his school. It gives a nice sense of nuance to the social commentary here. The message is clear. Money is a great thing to stand up against until you know you need it. Also, the show runner knew the show has been cleared through the fifth season at least (we've just started a couple episodes of 4), so I don't think that's quite the case.
The Nemisis reminds me of the episode with Sarah G. Latto. It shows Gumball can indeed be the bigger man and help out those who are actually injurious to his well being. He took pity on a stalker instead of calling the police in that one. Not the safest and wisest thing to do, but oddly heartwarming. It's great that Gumball and Darwin actually took some pity on Rob Dr. Wrecker and guided him on his path to evil, which will no doubt bite them on the butt in a later episode. But you gotta admit, they took the time and effort to guide someone who hated them and vowed revenge (for stupid reasons if you think about it. They only remembered Molly after investigation, and they actually knew her). Sometimes Gumball can be a real jerk (and most times he owns up to it), but sometimes he's actually the surprisingly sane one in the series.