I think this issue is a bit more complex than you may think. I understand completely why you may come to that conclusion. More time should equal more work yes? After all, I haven't checked any games out in quite a while. When I came back last night, I was expecting quite a bit more than there was.
Sitting in your room for weeks in quarantine feels good. You feel so productive when you can't even go outside for a walk. Your creative juices flow like never before. Quarantine is energizing. No, it is exhilarating!
But seriously. Content creators are people too; try to remember that sometimes.
However, I don't think Corvo here is 100% correct either. Yes, I can understand how the quarantine can be bad for creativity, the bigger hit would be on motivation. Not knowing how long it will last, is hurting everyone. It's easy to think "we have x amount of time left so let's wait a bit before getting started" and repeating that cycle. As for creativity, most people in any sort of creative work have plenty of ideas they want to incorporate and likely have a list somewhere. Due to time, or motivational problems, the list may never shrink, or content never gets added.
Also, there are potentially missed opportunities for those who have lost their motivation. With so many many things from movies, to games getting delayed, it is prime time for devs to pump out their work in an attempt to attract potential new players, which in turn potentially means more income. With so many people unable to work right now, and assuming only the minority make their games full time, it's easy to see the potential gain vs loss for this community during this time.
The other major issue I see, and it is a big one, and IMO affects things quite a bit more than anything I've mentioned so far, their families are home. I can assume many of the devs have children, wives, girlfriends or live with parents, siblings, etc. With everyone at home at a time like this, it becomes considerably more complicated to make games with certain genres most would consider unsavory. Imagine being a 20-year-old college student, still living with your parents, you're making an adult incest game where you fuck your siblings and mother. Now imagine getting caught testing, or writing your game. Now what kind of awkward conversation do you think that would be?