The belief efforts to protect people from calamity will only lead to them being more careless, and bringing on more calamity.
This is a fallacy because it (a) assumes people can adjust personal risk to replicate an incomparable situation, and (b) it confusing risk-taking and risky behavior. "Risk-taking" is a neutral term that includes anything that increases risk in some way, such as operating a machine at a higher speed. This usually is done to get some other benefit. "Risky behavior" is foolish, feckless, or sloppy behavior that has no intrinsic utility to the person engaging in it.
An example of the curmudgeon's fallacy is the erroneous claim that safer cars make for careless drivers.