The amount of button pressing, clicking, and micro of the pet required, take away a lot of the fun.
^this is the real meat of the argument here. I LOVE playing the ranger because you have to be good at micromanaging in order to be really effective. For instance timing pet switches before Rampage as one activates in order to get might to stack on my pet properly is key to getting the most out of that elite. Switching pets during it gimps the skill. I also have people that ask me how I keep my pets alive in dungeons and fractals ect... I wish people could see me playing, i must look like a crazy person with all the button mashing. I get hand cramps playing ranger due to all it takes to keep both myself and my pet involved/alive in tough fights. I like the stress of it. I play other toons to relax tbh.
I guess if that appeals to you then YES ranger is very fun. The fact is, as it always has been, you aren't going to enjoy it very much if you just want to ignore your pet. You are also going to suck. So, if you don't want to be watching 2 health bars, more cool-downs, and constantly thinking about which pet skills you have and when to switch them in and out, then NO, ranger will not be fun.
Love you pet or leave the class. I personally love the pet system.