You might be not too emotional.
Or being a macho guy or a cruel emotionless bitch, not caring about those "commitment" things at all.
But spend some nice time with someone online 5-6 times, like it or not, you will get involved, emotions will start to sparkle between you two, you will start to feel something for that living being on the other side. You will start to care about that person.
And in the end - you might get hurt ... or hurt someone and feel sorry. Feel guilty. Feel like you betrayed someone that might have loved you. Just like in a real-life relationship.
It's amazing. Despite you try to convince yourself: come on, it's only online. Well, online matters too.
Because, like it or not - you are in a kind of relationship. Face it!