"Vaccine mandates from businesses are illegal." Why would it be illegal for a private company to only want to employee people who are vaccinated? A company can, and should be allowed to, choose who they are going to hire as long as it isn't discriminating against any protected class. Requiring vaccination would be no different than a professional sports team having a provision in a contract to prohibit an athlete from riding dirt bikes or other dangerous activities.
"The fact that they're trying to do it is disgusting and is simply about money and liability." Like most rational business decisions it is about money. They don't want to risk losing money because they have to close down during an outbreak among their workers. It is also about good customer service and protecting their employees. If they have to close due to an outbreak they can't provide their customers with the goods or services they need. If there is an outbreak among employees it puts the health of other employees at risk and if they have to close because of that outbreak it puts the well being of employees at risk because they are not being paid for the time they are closed.
Will/should all employers require vaccination? No, each business should weigh the positives and negatives and decide for themselves if they need to have such a mandate. They may decide it is worth it or that a mandate would cause them to lose too many unvaccinated customers or too many good employees. One wonderful part of our economic system is that businesses can hire and fire people based on who they believe will make the business successful.
If you think businesses saying they will only employ vaccinated people is bad just wait. Some business are already starting to require vaccination from their customers before allowing them to enter their business. cnbc.com I wouldn't be surprised if some landlords start requiring vaccination in new, or renewal, leases to "protect the health and welfare" of all of the tenants in the building.
Maybe if employers, stores, restaurants and landlords started denying to do business with unvaccinated people the vaccination rate would go up dramatically.