So, just to be clear, I agree. However, if the asker specified already their intention to try and play D&D with criminals doing crime jobs, then context and tone becomes even more important. If I come in and tell them flatly that it’s a bad idea and D&D sucks at doing anything but D&D (a common refrain, last couple years), I’m being a bit of a donk. If I explain what I like about Blades for running a gang of thieves game, and point out that Blades is even a fantasy crime game, and/or explain why I don’t think D&D is good what they’re trying to do, I’ve given them useful information, and avoiding coming across like I think I know better than them.