Personally, I think it's more interesting and fun to have to heal AND dps vs just 100% healing uptime anyways.
Even when I have to heal all the time, it's just that, casting healing spell after healing spell with a bit of helpful skills sprinkled over it.
Nothing I have to really balance, or strategize about. No big drawbacks.

But every time I enter CS, I make a decision. Is it worth it? Can I risk it? How long can I keep this up? Which skills should I have on hand, how much dmg do the opponents do per enemy GCD, so I know when to switch back?
The amount of "healer-thinking" is so much more than if I could just brainlessly spam heal, heal, heal all the time.

That said, I really enjoy it when normal content has a bit more healing requirements than the current average. Like Weeping City, for example
Definitely requires more (and more aware) healing than other non-savage content while still allowing for the freedom to not JUST heal fulltime.