The reasons why people play the FF games vary from person to person. Some do it for the story. Some do it for the gameplay. Some do it for the exploration and etc. Yes, the FFVII:R could have been a turn based game, but it would not be as successful with the modern times. The world has not remained in a frozen time chamber for 20 years where nothing changed. A lot of older fans would buy it instantly with some newer people getting it out of curiosity, but that is where it would end. It's more of a challenge for the company to make an ARPG than a turn based style game at this point. Even if one were to exclude the online titles, that's still 12 mainline numbered games where experience has been gained over time with some variation of turn based combat. It doesn't necessarily mean that there won't ever be a mainline big budget turn based game again, but there's obviously support behind ARPG titles as well and room for growth.

If one does not support the format of the FFVII:R, then one should talk with their wallet. The title, and future ones, will continue to make changes. If one does not support said changes, one can always play the older titles still. If that isn't enough, one can always see themselves out the door and partake in a different series' new installments. As long as the FF brand have existed, satisfying every person is impossible at this point.