There has to be some limit for the company. Let’s forget a minute about big evil corporation and take a little local company that hire a new person that is needed to run the shop. If this person is absent unlimited and you don’t have the funds to hire a replacement, should you just close the shop? It doesn’t mean we can put an arbitrary limit on sickness but rather than at some point the company have the liberty to let you go if you can’t fulfil your part of the contract anymore in the forsable future. It doesn’t mean there shouldn’t be a system to help the sick person recover, but maybe that’s not the company’s job past a certain time, and rather the role of social/health insurance.