I use insightful when I've learnt something I didn't know, so it's still a pretty valid response and I'd hope people would use it such a way, and not for the troll aspect.

If this comment is a little long, please see the tl;dr towards the bottom.

I like the anonymity with the responses. Quite often if I see someone having an argument with another I'm not too fond of, I'll back up the other persons comments with "Agree" and feel good about myself for 2 minutes until I begin to feel shame.
It just occurred to me, I'm a terrible person. On the upside it shows I have some kind of morals and remorse, but does that balance out all the horrible things I've done?
The fact I do it over and over again probably negates any remorse I inevitably have in the end, and means nothing. The worst thing is, I believe I'm too vengeful of a person, with the inability to excuse a persons actions resulting in long-term grudges. This is reflected in my actions, such as what button response I press to a forum comment, and the reasoning behind it.
I'm the kind of person who would never harm an animal, even so much as a spider, but if a human wrongs me in any way, I will make it my lifes goal to ensure their suffer is real and prolonged. Cut in line when I was waiting in that queue for 10 minutes? I'll take an item out of your shopping basket and throw it in the opposite direction. Cut me off in a lane? I'll break every road rule ever written, get in front of you and drive at 15 miles per hour, even if I'm late for work. My personal and professional obligations are second to your suffering should you cross me. You can count on that.
Is this "normal" or expected behaviour of someone my age (32)? I don't believe so. I've tried speaking my counsellor about it, but she cut our sessions short and said I needed more professional help than what she could deliver. Well, at least she's honest.
Have you ever spoken to someone, and as they are describing their perfect life and job, you feel a tingling throughout your body most likely caused by nerves.. you're totally paralysed, unable to move, or think about anything other than flaying their skin and wearing it so you could lead their picturesque life?
I was diagnosed with HFA (High Functioning Autism) later in life. My parents never seemed to care, so my personality and social ineptness grew wildly out of control over the years. Relationships and friendships are impossible to keep, and I have no idea why I'm still employed. Kudos to my boss for putting up with me for 4 years.
Suffice it to say I have little affection, empathy, sympathy, or any emotion towards other people. But animals? I just love those little (and big) guys.
I guess what I'm trying to say is, it's hard to think badly towards an animal, so if they used forums then people would vote their response accordingly and respectful, always managing to choose the right one depending on how the author made them feel. People have such variable thoughts towards one another making the responses void, nothing, nada. They don't mean anything because that "insightful" could mean "Lol ur stupid", or it could be a respectful "I've learnt something today, thank you".
Take this scenario as an example; You've created a comment that you're extremely happy with. It was well thought-out, good for you! Somebody you thought was a nice person gives it an Insightful (and they actually meant it - not as a troll). You now think that this person you respected is mocking you. How do you feel? Not very good imagine.

tl;dr: Probably not the best idea.