Then you run into the problem of infinite loops, which nothing can prevent (sans `main { exit(-1); }` or other forms of losing turing-completeness), and are worse than crashes - at least on crashes you can quickly restart the program (something something erlang).

try-catch isn't a particularly complete solution either if you have any code outside of it (at the very least, the catch arm) or if data can get preserved across iterations that can easily get messed up if left half-updated (say, caches, poisoned mutexes, stuck-borrowed refcells) so you'll likely want a full restart to work well too, and might even prefer it sometimes.