Interesting subject - but then again love always is
It's my belief that we seek love to find our way back to the true sense of our selves - which I believe to be unconditional love. I believe that the unconditional love we are is oneness and that is what we are seeking.
Our seach takes us outside our selves trying to find it in another person, but as we develop within we will grow tired of a relationship because we have now explored and in a sense integrated the sides of that other person we needed to develop further within. As we start figuring out that oneness can't be found outside ourselves our relationships will change, it will be more and more based on unconditional love depending on how close we are to our own truth.
I don't think conditional love is bad - I think some people need just that before realizing that keeping to look for love in another person means you will never truly find it. We are all at different stages and even conditional love is unconditional - because unconditional love consist of ALL. And even conditional love will help us grow, develop and move on toward oneness.
Love Dorthe