There will always be whiners
When something new enters the game, there will always be whiners. Obviously, any new feature won't be exactly what everyone wants, but the fact that RF raids run constantly suggests that it must meet some sort of demand. If it didn't, it would have simply spiked in popularity and then faded away (kind of like the arena).
The thing is, adding RF does NOT CHANGE THE GAME for people who don't like it. It's just another option for people who play. None of the content that you enjoy has been altered in any way by the addition of RF.
It seems to me that the main complaints against the existence RF are:
1) "There are fewer people to do real raids," and
2) "People are getting gear that I had to work for."
My reply is that the second point is the answer to the first. By making medium-tier gear accessible, players will have an easier time equipping for real raids, and the raiding population will go up.
And besides, it people elect to do RF over the real raids... while that may be their loss, it's their choice. There's no sense in complaining that, by using other features of the game, other people aren't doing what you want them to do.
So, thanks to the devs for adding RF. All new features are appreciated, even if it's hard to tell from all the whining.