Here's why I don't like magazine disconnects. They interfere with the safe consistent operation of the gun in other situations. For example, the Ruger Mark III pistol has a magazine disconnect. You have to "dry fire" the gun in several steps while cleaning. That means, rather than remove all magazines and ammunition from your work environment while cleaning, you need to keep a magazine (unloaded yes) to insert and remove at various points in the assembly and disassembly. It makes the whole process significantly more complex.
It also means that you can't easily practice with that gun without ammunition. Although the gun is safe to dry fire, when you cock the hammer, the slide will lock back. Without the magazine disconnect, you would simply pull the slide back and let go an you'd be ready to dry fire. Dry fire activities are valuable, but they're also a place where people make mistakes. So it'd be better all around if you could remove all ammunition and magazines from your environment when doing it. Adding complexity to the process makes it more likely you'll commit an error.
I prefer the simpler more consistent operation of guns without a magazine disconnect. But my very first lesson to new shooters is also that a gun with an empty magazine can still be loaded (and I use a dummy round for that lesson).