I've also worked with many colleagues who were great at their jobs, but that's all it was for them - a job. Their passions (which was sometimes just their family) lied elsewhere. They were just working to support that and were perfectly happy with their lives. I wouldn't try to take that from them.
This suggests that it's unacceptable to care about doing your job well because you enjoy it or simply because your morals compel you to work hard at what you do. I don't think there's anything wrong with someone choosing to work hard for these reasons if that's their choice.
Spending your passion on your own projects or OSS will yield you better returns 9 times out of 10.
I think overall my objection is to blanket advice I've heard during my life about how much care I should put into my work. I have never been able to be effective (and as a result have had issues with) doing meaningless work which I didn't care about. I have also had issues with continuing to care about work which people I work with didn't care about.
It's clear that a carefree approach works for some people but in this case it seems like better advice for OP would be to explain how to find jobs where people do care rather than trying to tell him (and other people in that situation) to just deal with it.
Is it nicer to work in a product/organisation you are passionate about? Of course, it doesn't mean this passion will last, or that it will be rewarded, or that it will even be healthy for you (one of the jobs I burned out from was exactly the one I was the most passionate about).
Building products follows the same patterns, even if the underlying technologies are different, or if you work on a product in a very different market/industry. It becomes all more of the same: store data somewhere, pull data from somewhere, transform some data to some other format, write some business logic, develop an interface, develop an application (web, desktop, mobile, embedded), deploy your systems at some server, monitor your systems (or implement telemetry if working embedded). You don't need to be passionate to work like that, you just need to be professional.
By doing that you also avoid the common pitfall of being exploited because of your passion.
But you're right though, when I am in flow, those 8 hours go by a lot quicker :)
If you're only working places you're passionate about, you're really winnowing the field of possible employers. I say this as someone who's working at a company I generally respect and am passionate about the product of - I think more than most of my friends who work in the field are about their work. If I wanted another job, there's not a huge pool of companies I would even want to apply to.
If I lose my job, or quit, then I'm often going to need to apply and work somewhere that's not a good fit. I can hold out for a bit without a job, but there's no promise that another company I'm also passionate about is hiring for any position I'm qualified for.
We don't know that. That's one stereotype theory that comes to mind when we hear "big company", but that's not the only plausible explanation.
Also, some people told to do the bare minimum at their jobs will think "Alrighty!" But the same advice could be very counterproductive for people who take pride in their craft or professionalism, or who want to see the mission happen. Those people should be nudged towards improving their situation (either at the current place, or somewhere else), not destroying their strengths.
Ended up horribly burnt out, to the point that I'm still struggling with the idea of working 2 years later.
Your colleagues have the right attitude. They are doing the absolute bare minimum to collect a paycheck and go home. I suggest you do the same.
Caring about your job is only acceptable if your labor is sufficiently rewarded, you own the company, or if it's some kind of non-profit or public service job that actually benefits society. If you're working for a for-profit organization, the goal is not to work hard, but to be exploited as little as possible.