If it was written in Lisp, there would be Cars everywhere.

In case my sarcasm detector is malfunctioning and this is not a joke:

A "slower" language would just mean that this universe's "ticks" would take longer. Cars would be just fine.

https://www.xkcd.com/505/

I'd just as easily assume that it is -- progress in physics tends to unify piecemeal complicated theories as different aspects of simpler rules.

No, but it might be a whole lot of them.

I'd prefer slow to "in the best case, everything blows up at once - in the worst, there's a memory error that if exploited, turns your world into a dystopia".

Not sure speed is relevant here. Those inside the simulation would not notice the difference, would they?

The Java simulation would be just as fast as the C one in the median case. The two problems with it are that 1) the big bang would have taken forever to start up and 2) the universe would eventually skip a beat for a stop-the-world GC cycle.

If the world is simulated then "real" time simulation speed does not have any influence on our experiences inside simulation. For all we know the next-up world can have different dimensionality from ours or no at all.