The result is probably that people who actually give a damn about their coworkers work, even when they are sick, and the people who don't call in sick when they aren't.
If they really cared about their coworkers, they would stay home and get better. If they care about being seen to be at work (for whatever reason - maybe they have a toxic culture of presenteeism) over their coworkers, they'll come in.
Of course, if the cost of staying home is that everyone loses a bonus, we can come to some arrangement. I would be happy for my sick colleague to take it easy and just mark time while the rest of us covered their work for the day, and I'm sure we can send them off "to gather supplies" or some such if we need to. You get what you incentivise; you incentivise employees to come in when they're sick, that's all you'll get.
A constantly sneezing worker will be unprofessional, prone to making errors, much less productive and endanger his/her co-workers. Now, granted, this is Amazon so no client will see those warehouse employees and I guess their processes are so airtight that one employee making mistakes won't have such a big impact (four-eyes principles or whatever). But it still seems pretty inefficient to me.
In Switzerland, some companies have insurance that covers sick days for employees - if your employee is sick, the insurance company will pay the wage during that time. This is mainly meant to cover longer sicknesses in smaller companies, who otherwise might get into real financial issues, but it also has the (in my opinion) desirable side-effect that a company is actually better off sending you home than having you at your desk as a half-productive zombie.