I think that here, lazy means "do as little as possible" and hardworking means "always do something", it doesn't mean people do or don't do as they are told.
Lazy stupid is fine because these people will execute the order to the letter and then slack off. If the order is clear, there is not much damage they can do. Hardworking stupid will try to do more and mess things up.
So if the order is to clean the toilets and the guy notices a leak.
The lazy stupid will clean the toilets
The hardworking stupid will clean the toilets and then attempts to fix the leak, mess things up and cause a flood
The hardworking clever will clean the toilets inspect the leak, try to do something, realize there is nothing he can do it and call the plumber
The lazy clever will take a look at the leak and call the plumber. He will not clean the toilets because he knows the repair will make a mess and it is therefore useless.
Lazy stupid was useless in that situation but didn't make things worse like hardworking stupid. Both clevers did the right thing, the difference is that hardworking wasted time but he executed the order, a reliable worker. Lazy may not be as reliable as a worker because he didn't execute the order, but he is the better decision maker.
You do understand that cleaning a damaged toilet is an invitation to a flood of excrement? Sometimes just touching a leak is enough to get the thing to explode.
So anyone not calling the plumber (or skilled at being one) who tries to clean it may end up in the dumps.
An actual plumber will clean it after fixing or during fixing.
Lazy stupid is fine because these people will execute the order to the letter and then slack off. If the order is clear, there is not much damage they can do. Hardworking stupid will try to do more and mess things up.
So if the order is to clean the toilets and the guy notices a leak.
The lazy stupid will clean the toilets
The hardworking stupid will clean the toilets and then attempts to fix the leak, mess things up and cause a flood
The hardworking clever will clean the toilets inspect the leak, try to do something, realize there is nothing he can do it and call the plumber
The lazy clever will take a look at the leak and call the plumber. He will not clean the toilets because he knows the repair will make a mess and it is therefore useless.
Lazy stupid was useless in that situation but didn't make things worse like hardworking stupid. Both clevers did the right thing, the difference is that hardworking wasted time but he executed the order, a reliable worker. Lazy may not be as reliable as a worker because he didn't execute the order, but he is the better decision maker.