Careful, if it gets out that you wrote the code to automate your job as a coder while actually at your job, your company most likely owns that IP.
Yes, in theory. In practice, an employee's power to negotiate wages is limited. At some point, the employee just needs to work to eat/pay rent/etc.
Now, in most areas (of the US), software developers already are paid generously. Even in lower paying secondary markets, software dev are usually paid significantly above local averages.
And, anecdotally, that pay is often for a much "easier" job, where "easier" means less stress and fewer hours than professions that generate similar salaries (engineering, accounting come to mind).
Cause they have more power than you. That's about it.
These tasks might not be worth selling as a service, they could be relatively trivial yet very context specific... I suspect this is the case, and that the real issue is with the employers lacking the insight to realise the these tasks _should_ have been automated and have the initiative to do so as soon as possible.
More specifically they probably neglected to employ people between the grunt worker and executive positions that would _have_ the insight to automate these tasks as soon as possible. That's basically corner cutting in terms of employees, in which case perhaps they deserve to be exploited, the funds are correctly being appropriated to the people who realised they needed to be automated.
EDIT: to be clear I don't find it 100% morally acceptable, going behind the employer like this is underhanded of course, but it can be somewhat justified as I outlined above. I suppose the alternative is to explain to the employer how it should be done and do so and hope to gain some kind of promotion or compensation, but that entirely depends on the moral standards of that company.
Can you expand on this? I don't understand the anology
Perhaps they're saying that the employer has to (indirectly) pay for a parking lot to accommodate them?
For those that might say that a job description sets product based terms for employment, it's rare that they are offered that way. Almost all the job descriptions that I've ever seen (and all that I've written) have some sort of phrase to the effect of, "...and other work as might be assigned." A job description isn't a Statement of Work, they're usually just general expectation setting devices.
EDIT: And I would add, for anyone that has automated their job in this way...what you should really be doing is scaling it up, and finding other companies who are probably paying employees to do the same thing. Then start your own company that does whatever this task is as a service.