You haven't seen people on the pro-rescue side making troll threads and calling people names for disagreeing with them then. You want to talk about logic though, so sure, let's talk.
1) It's awkward to use due to the delay between it moving the player in question and from when it's been used. There are also some weird interactions with certain game mechanics since knockbacks, teleports and pulls all override each other.
2) A lot of players find it disorientating when used on them, especially if they're a player that had a plan in mind for moving to a safe zone. Imagine Rescueing a DRG or RDM and they suddenly flip away back into danger because they were intending to flip away from the danger prior to your attempted Rescue.
3) It also completely removes individual responsibility and promotes godmodding. For those that don't know, godmodding is a rp term for when one player conducts actions that control another player directly. It's shamed and people used to blank people if they pulled it even a tiny bit. This is a MMORPG and Rescue falls in the same vein. You are moving another player. Regardless of how frustrating another player might be, it breaks a certain boundary that shouldn't be broken. People will argue that long cooldown makes it okay or that healing is also controlling another player(when it clearly isn't).
4) Most healers aren't skilled enough to use it properly either. In addition to the delay between cast and activation a lot of healers are woefully unaware of the fact that rescue moves their target to where they are standing when they cast it, rather than where they are located when the ability goes off. In combination with the earlier issues, most healers also don't have the aptitude to assess their team and make decisions on whether the player in question can handle themselves or not. That DPS that just hit one of their movement abilities making them fall into the danger zone right after said healer Rescued was playing fine for 90% of the dungeon. That Tank that was standing at the edge of the healer's earthly star/asylum/sacred soil during a pull was moving out of the way of a bunch of aoe markers before said healer dragged them back into them. Said tank had never moved out of their abilities prior, yet again, said healer didn't bother to judge the situation.
5) On top of it all, we have people abusing it for their own amusement. Some people enjoy Rescueing players to their deaths. Some people use it to leash their tanks, pulling them along through the dungeon every 2 minutes. People in this very thread have admitted to doing this even.
Do what you will with these reasonings but at the least please respect the fact that they were laid out without calling the other players in this thread incompetent and without aggressive name calling.