It's not so much "carbon" or "aluminum" as it is design and intended use.

Fancy race bikes are designed with weight and performance first and durability well, on down the list. Those bikes (and wheels) do indeed come with weight restrictions limiting manufacturer warranty coverage.

You can find carbon that will hold up fine, you can find aluminum that may not, and of course you can find carbon that won't hold up either. My guess is a carbon rear triangle or seat stays will not be an issue whatsoever.

Some people are just of the impression that carbon explodes if you look at it wrong! Don't let them discourage you!! And have fun picking out your next bike!