Obviously not considered a serious enough problem to frighten the Regulators into action.
Not the case at all. To lose all engines in a modern transport jet...
1. ...is EXTREMELY rare.
2. ...will have an outcome that is largely dependent on luck. A transport jet isn't a 172 that can glide forever, at a very slow speed, and can stop in a confined space such as a narrow, straight stretch of road. You'd pretty much need to be at just the right hight relative to a VERY long runway in favourable conditions.
You're likely to have degraded control authority, an impressive sink rate, no way to dissipate excess energy, a longer gear extension process, more than usual drag with the gear down, and little or no chance for a second option if one action isn't the correct one. In short, you've got to get everything right the first time, in a situation that is completely unpredictable and which has never been flight tested. If the stars don't line up just right, you're likely to die.
In the sim, it may be trained, but not tested. Personally, there are other failures which are far more likely, that are fatal if mishandled. I'd rather spend my sim time on those scenarios.