Consumers wont buy it if plastic wrapped options are allowed. Clear plastic allows transparency into the object that is being purchased while at the same protecting from external contamination. For example a clear plastic egg carton allows you to see if any eggs are broken without risking getting egg goo on you.
You can look on the underside of the egg carton to see if any of them are wet from broken egg leaking into it, or open the carton and gently lift each egg to see if they stick.
But I do agree that humans are pretty likely to take the easy choice here, which is why we need to take those choices away so we can more easily make the better choices.