Yes, I am serious. I find it shocking that you are not prepared to take a very simple step to protect animals who rely utterly on you to look after them and keep them safe. Even if you never make a mistake which gives the fox access to your rabbits, which is a big "if" human fallibility being what it is, the presence of the fox nearby is likely to cause your rabbits continuing stress which itself may kill them.
So what do you suggest then? Shall we all go back to northern France which is where we came from at the end of the Ice Age? Except the foxes came over with us.
Foxes and other ground dwelling wildlife are cleared from land in the building process. The foxes we see in urban areas either visit from surrounding unbuilt-on areas or have re-colonised built-up areas from outside because we provide them shelter and somewhere to hide, especially in the sort of dense undergrowth which grows up in suburban gardens over decades. They have moved into urban and suburban areas because we lay on easy food for them (pets and discarded fast food) and because they are losing, indeed have lost, their fear of us.
Foxes and rabbits are simply incompatible and frankly I would rather take drastic action occasionally than have the constant worry about whether my pets are safe.
Remember - you have to be lucky every night. The fox only has to be lucky once.