Trencher

They are changing the nature of certain monsters because some folks are perceiving monsters as humans.

I am of the opinion that lots of fey and similar creatures dont belong in a monster book at all and should be in an rpg encounter book.

And my opinion on orcs are that they are supposed to be the monstrous face of the industrialization of war and society in general but since they have been changed to "proud warriors of nature and peace" style orcs I kinda think they dont belong in monster books as well.

Monsters should be something that attack and kill you otherwise what is the point of statting them out you know?

Seen a lot of these posts on Twitter as well. What I think is happening is that they are trying to move away from the less than savory origins or races like Orcs. Like it or not they have origins in negative racial stereotypes. While working on an article for my own sanity a few months ago I sourced some of the materials WotC is now trying to pull away from. (Article if you are interested. Reference links at the bottom.)

The other change I was seeing is the Drow, moving them from an inherently evil race, to having a pervasive cult that shadows them. One of the things I find interesting here is while you have similar racial undertones, you also had this anti-feminist aspect. That being, the Drow are a matriarchy which is inherently corrupt and evil. This also translated some wink and nod sexual content for D&D or should we say D&D/s. 

What I've said in other threads is that if you like the old lore, that material is still out there, and available to you. No one is saying what you can play at your personal table.