Software does get treated differently. The perception being that is is "soft", therefore malleable.

Our requirements group prepares requirements for 3 groups: Mechanical, Electrical and Software. They are familiar with and use the processes required for mechanical and electrical specifications. But when we (the software group) ask them to follow the same processes they follow for mechanical and electrical, they claim that those processes are too slow so they would not be able to deliver specifications to us in time. So they would need to issue preliminary specifications to us - but that would be extra work, so better to keep using the current processes.

Then, the upper level managers state that the business case for using software at all is the flexibility software allows and the speed it can be developed. Therefore, if we follow processes oriented for creating hardware, we negate the business case for using software.

Of course, when we get incomplete/ambiguous/self-contradictory specifications, we still get blamed for not delivering what was wanted. And when we do ask for clarifications, we get blamed for the delays introduced by the need to respond to our questions.

So why do software developers keep developing software?

At least for my team, most of the time we have fun making our software make electro-mechanical "contraptions" do things.