Hi Rich,
Mine certainly were installed "never to be removed"/burglar proof. As you say, you'd need an angle grinder to take them out.
It's no comfort, but we've done fiddly bits of touching up over 5 years, & although they don't look pristine, at least they're free of rust.
The upstairs ones are the real b#######!!!
If you think about it, a certain administrator has never had them (only shutters), & his house now is unoccupied without being broken into.
It's about how comfy you would feel if you did away with them.
All the best,
Mike