Passive income is never really passive. Real states, stocks, bonds, other properties,... everything requires you attention at the end of the day. The most interesting fact is how the different economic classes have a very different distribution of assets. Middle class tend to have their living place as main asset, while wealthy people tend to have stocks and "other", such as art.
But those attention that you need to put through isn't as intense as an actively managed income stream, just check it from time to time and you're good to go. You're not going everyday to the tenant to ask for rent right? The fact that you're stressing in passive means you're greedy because you want things to speed up and you're also doting.