Unpopular opinion: Mini-split units get installed in dumb spots way too often

I notice a lot of mini-split systems in homes during my flooring work. The indoor units are sometimes placed way too high or tucked in a corner. I heard poor placement can mess with airflow and cooling. But I'm not an expert, so I want to ask you pros. Is there a basic guide for where to mount these things? I've seen techs put them where it's easy, not where it works best. What should we look for to avoid common mistakes?