They are disparate conditions. Errors happen in response to conditions that occur during the execution of the application. Exceptions happen in response to conditions that occurred when the code was written. Very different things.

It is highly unlikely that you want to handle an exception. It's the runtime equivalent of a compiler error. Do you also want to handle compiler errors so that your faulty code still compiles? Of course not, so why would you want to do the same when your coding mistakes are noticed at runtime?

There are, uh, exceptions to that when it is necessary to handle exceptions, but if it you see it as routine you're doing something wrong. If you overloaded that with errors, forcing it to be routine, you'd have a nightmare on your hands (like in those other languages that have tried it).