Look I'm not going to sugarcoat it at all, as medic is my main faction to play on, and I enjoy it most of all. But sometimes after you've spent some time getting to know some of the "personalities" that some rebels have, and how they quite often bad mouth some of the medics, it is no wonder why the medic will go out to the revive location, pick up the person known to be a bit of a scumbag and leave the scene straight away. This is purely to prevent the toxic comments that some medics receive, as some medics feel it's not worth the time and effort to do anything else about it. Not to mention the protocols that medics must maintain and server rules that must be followed for the medic to be able to stay within the Altis Paramedic Service.
As you've spoken about response time taking "forever", once again this sometimes is due to the medics having to adhere to protocols. For example, medics are not to enter a combat zone until 2 minutes after the last gunshot was fired, or it has been cleared code 5.
So at times when medics are attempting to respond, there are trolls who see medics moving in to revive people and begin shooting furiously. Therefore, the medic must back off out of the combat zone again and wait.
Just another point of view to enlighten you and some other people who take the time to read it.