You might as well ask should businesses train employees, give them the proper tools for the job, and hire enough people to do the job. If a company doesn’t do any of those 3 things, they are essentially shooting themselves in the foot. The same is true for health care insurance, only more so.
A company’s goal is to make money. I’m sorry if that hurts your delicate sense of fair play, but it’s true. If a company makes no money, it goes out of business. If a company makes a lot of money, it generally expands so it can make even more money. The employees of a company are essential for it to make money, and the good part is the more money the company makes then the more people it can employ. More people working is a good thing, I’m sure we can all agree on that.
However, if employees get sick and don’t have health insurance they might end up loosing their job as they either can’t afford the health care to get better and can’t return to work, or they go heavily into debt to get the health care they need but end up ruining their life trying to get out from under all that debt. In both cases, those former employees are now no good to that company. When they leave (when any employee leaves for any reason) a company looses all the time and money they have invested in that person training on equipment and procedures, on the job training, and just general knowledge of how things get done at that company. All of this will take time and money for a new employee to learn.
That was looking at the drastic side of no health insurance. However, if you have health insurance, even the smaller things are better and take much less time to recover from. Consider something like the flu. If it would normally take a week to fully recover and say 3 days off work for a healthy person, imagine someone who has many other health issues due to no health insurance trying to fight off the flu it will easily last twice as long, and keep them away from work for twice as long as well. To a company, those sick days are like loosing part of that employee as if they were quitting. There are roughly 2000 hours in a normal working year, and it doesn’t take much before 100 of those hours are gone due to illness (real illness, not from hangovers or such). At that rate, the employee has been absent for 5% of the work year the company has gotten 5% less work out of that employee.
That is why most companies that are able to, invest in their employees through their health insurance and other means. The government should encourage companies with a law that forces them to pay at least a portion of health care insurance, if not all of it for employees. If employees remain healthy, then they will be fairly happy and at work more earning everyone themselves and the government included more money! And that makes us all even happier.