I've observed increases in this type of behavior when things aren't going so well.
When people feel like they are shipping software that makes a difference, they want to be there. If it's only this individual, then it probably speaks more to their behavior than anything systemic. But if it is others too, I would look more broadly.
The notion that this is a valid excuse for telling your boss, "hey, pops, I'm not feeling engaged this morning, gonna be in later" is a new one.
Maybe that's a good thing. Maybe not. But it's definitely a different thing.
But you get in and spend a lot of your time fixing bugs and working on old, monolithic codebases.
People want to make a difference, employers sell the vision, and then there's this mis-match and you have the disengaged worker.
I think the problem is the reality that most software jobs need skilled workers, but skilled workers are often seeking enough intellectual stimulation from their jobs to make a difference, and a lot of this work isn't the the type of life-changing envisioned.
Before that, it was possible to take a job after graduation and stay with the same company until retirement. A worker's loyalty to the company was rewarded in kind, with the company's loyalty to the worker. People got raises and promotions. They grew roots.
Now, there is zero corporate loyalty. If you can't predict a profit for this quarter for your specific individual contribution, regardless of how hard you can work, you're fired. But you will come crawling back when we need you again, won't you?
The workers have responded. If the company stops making the work worthwhile, the worker will slack off or jump ship. If the company force-feeds its Flavor-Ade, the employees will just puke it up as soon as it's safe to do so. If the company tells baldfaced lies about itself, the employees smile and nod, while thinking about the rude gestures they would like to be making.
The "lack of engagement" is because the employees know that management cares about them not at all, but the forms must still be honored in order to receive the paycheck. In short, your company is bullshit and the workers hate it; they are just using it to get what they need and will ditch it the instant that a better deal comes along. We are all mercenaries now.
We will disobey whenever it's more convenient for us, and we think we can get away with it. Because the company executives are just our bosses, not our friends or our leaders or our prophets. If they fire us, we move on to the next bosses just like them. We're not going to bust our ass to earn them another dollar. Maybe if we are freshly fallen off the back of the turnip truck, we will go the extra mile, but it doesn't take long for those folks to learn. So the disengaged worker is the default. We learned from our elders, who were forcibly disengaged by their employers.
And since my fortunes are not tied to those of my employer in any meaningful way, I will not stick around to help bail out a sinking ship. If you're going down, I'm not even going to plug the leak and call for help. I'll just grab a lifeboat and be on my way, thanks. It will probably even be an even smoother ride, as I won't have to worry about any rising tides raising my boat.
The problem is that a programmer described above would not be hired by your company and simultaneously wont recognize your company as a good place for him from job posting. Even admitting that you dont mind fixing bugs is other peoples code might make you sound as lesser programmer in current culture.
Otherwise said, there is mismatch between what companies need and what they reward.
It's not just skill, it's also a level of creativity that one needs to do things like programming. And that creativity is often absent when the work is too boring.
I assure you it can be done at 9AM when you're a little tired.
Whether or not you should have to be at work at 9AM is another matter, but this idea that you can't possibly get anything useful done unless you're in the zone has been oversold.
[1] Perversely, I miss burning wood; as a kid I cursed the woodpile, but its good exercise and you can get a lot of thinking done while you do it.
I've worked in jobs I wasn't engaged by, was able to finish university (not fun), and am starting to get bored at my current job, but I can't leave just yet due to external circumstances. I believe character is a big part of it, but it doesn't change the fact that I'm posting to hacker news during work hours.