I normally take any review on Amazon with a grain of salt. You can see trends, however, most folks only make reviews when they are mad about something. Also, you are dealing with consumer confusion as well. If someone can’t figure something out (I don’t want to say ‘dense’ here), they tend to blame the product.
For our pool, we have to have it gated (I think this is common place). If you have a deck, it needs a self closing gate. If you have just stairs to get in, they need to be collapsable. In our case, I put a sensor on my deck gate. That will only tell me if someone from inside went “toward” the pool. After we get a second deck put around the pool (still waiting for the deck company to get back to me :sighs), I plan on a similar set up. I currently don’t have anything on our collapsible stairs. It’s highly annoying.