I find that as I got older and gained more experience, my risk tolerance went down. In addition to 121, I still fly a lot of GA (I own my own single-engine piston.) I used to fly that airplane in LIFR all the time. Or across some very tall mountain ranges at night. A few times, across those mountain ranges, IFR at night. Even then, I knew that last one was foolish. But, amazingly enough in 25+ years and 6K hours of GA flying, I never once got iced up, as that was the one thing I avoided religiously.

I'll still fly single-engine pistons in relatively low IFR, and I'll still fly them at night. But at night I'll do everything I can to stay over the flatlands; I no longer fly over the mountains at night. As for the low IFR, I'll only do so in what I'd call 'soft' IFR, i.e. a marine layer that's clear above; I refuse to operate in 'hard' IFR where you're likely to be in IMC from takeoff to touchdown, and in conditions conducive to icing. And, I'll never again fly IMC in the mountains.

That said, even on perfect VFR days, there are times where an engine failure in a single is likely to end very badly. There are plenty of urban airports where if you lose the fan right after takeoff, you're landing on a busy freeway or a crowded neighborhood, none of which is likely to end well. That said, if you take that line of thinking to its logical conclusion, you'd never fly anywhere in a single.

So I just keep my airplane maintained as meticulously as possible (regular maintenance, oil analyses, digital engine trend analysis, borescopes every 100 hours, mag overhauls every 350 instead of 500 hours, vacuum pump replacements every few years, etc etc etc) and I accept the fact that yes, there are situations in which an engine failure has a high risk of injury or fatality. I just do my utmost to minimize the risk. And I think everyone's risk tolerance is understandably different.

And as for engine failures, I did lose one at night IMC (not in my airplane, but in a lousy flight school beater.) Amazingly enough, we happened to be on a LOC/DME approach to minimums at the time. The engine quit right at the FAF. Incredibly, we made it to the airport, just barely....thanks to a whole bunch of excess altitude my instrument student was carrying when we arrived at the FAF. Had she flown the approach at the correct altitudes, we'd have wound up in a shopping mall.

All that said, shooting an approach in a Saratoga at 600 RVR? YGBSM. No thank you.