Sure. But software shouldn't be able to make hardware damage itself.
Also, designing something like a steelworks without some kind of hardware-level override is so stupid it borders on criminal.
This is like saying "Sure, but car's shouldn't have anything that propels them forward...that's how car crashes happen."
The sole and entire point of control systems (aka SCADA, DCS, or ICS) is to make it possible for software to control hardware. And it's impossible to make *anything* that can't be broken or cause damage if it's abused. When you factor in things like blast furnaces, substations, or other real-time applications that involve massive amounts of energy (kinetic, electrical, thermal or otherwise), you're harnessing one hell of a big thing, and that means careful balances and lots of risk. You can't have a situation where there's thousands of degrees of heat and gigantic crucibles of molten steel and yet have it impossible for something to be done wrong.
It always makes me crazy when assholes (yes, that's my word for a novice who pontificates about the "incompetence" of actual professionals without citing anything concrete or meaningful) who don't have any experience whatsoever with control systems put forth their idolized version of reality that somehow means that everything can be simple and as safe as a Fisher-Price toy, despite the fact that these environments have never been foolproof in all of human history. Trains crash, pressure vessels explode, chemicals leak, boilers beer-can, transformers flash...it's always been that way, and always will be. Control systems make them less likely to do so for accidental reasons, but also allow an attacker to force it to happen for deliberate ones. That's the trade-off, and to this day it's still a trade-off that's had a positive outcome. It makes no more sense to back out these systems than it did for banking to go back to using adding machines, just because there were cyber security incidents early on in the financial sector. The next step forward is better security for these environments, which is in the process of happening as we speak.