Timing out packets instead of denying them could certainly be an issue (I run across this a lot with internet being down while the router and internal DNS is still up).
But your claim that “any OS will start to show trouble” is not how it’s supposed to work, nor how it used to work before 24/7 connections, nor even how it should work assuming you’re ok with phone-home daemons.
Of course it's not how it's supposed to work, but that is how it tends to work ;-)
An OS in general has a few layers with caches and monitors and resolvers etc, and if you block a few of them, in a partial manner, they tend to get in to an extreme version of the bus bunching problem. Windows still does that with their 'network identification' where sometimes something goes wrong in the probing process and the connection hangs on "identifying" indefinitely. And that's just a silly "optional" service (which should default to the public profile and only change from there instead of defaulting to no connection at all).
But your claim that “any OS will start to show trouble” is not how it’s supposed to work, nor how it used to work before 24/7 connections, nor even how it should work assuming you’re ok with phone-home daemons.