It all comes down to personal opinion and personal playstyle.

I for one play all 3 types of player like you do, healing, tanking and dps. Assuming this is content that requires a player to focus, regardless of difficulty or level. Personally, when I heal, I get tunnel visioned in keeping people alive (in heavy fights that requires much attention). When I tank, I have to focus on keeping hate, one or more than one mob, while keeping myself alive and using the necessary survivability cooldowns. As a DPS, I only have to keep myself from dying while dealing damage, and after a while you will learn your enemies' movements and act accordingly or instinctively, same with your rotations. Unlike Healing or Tanking, which requires initiative and reacting to what happens, DPS can deal damage using the rotations that they've mastered while watching the fight.

That saying, I enjoy all types of roles and experience enjoyment specific to that role. Glad you are enjoying the tank view though!