Following the issue that can be found here:
https://bugs.mojang.com/browse/MC-46776
And not knowing if new comments on old issues are signaled to the Mojang crew, I created this new issue to make sure the problem came to light.

I'll repeat here what I commented on that old issue:
I don't get why you changed the spectator mode in such a way! The best part in this mode was to be able to fly around, click any mob, and get into it, hostile or otherwise. Now we have to rename hostile mobs to have them stay? It doesn't make any sense compared to what this mode was about in first place!
And just for what? I mean, really? Because people complained about mob not despawning in special mob-pit or whatever? That's a legit reason to annoy everyone else? Just look how many other subject were created because of this change, from people whom complained about the hostile mobs not appearing anymore!
Please Mojang put that mode back as it was! This change suck!

And add that the author of the original issue said that they realized their idea was wrong and also want it back as before!