For a lot of us I think the criticism is more a matter of principle than anything practical. It comes from the same impulse that drives people to singlespeeds -- the love of simplicity. It may be simple to set up and simple to maintain and whatever else, but the fact is that it isn't fundamentally simple. The complexity is just hidden from you. I don't like having complexity hidden from me. I like to know what my bike is doing and understand how and why it is doing it.

Also, it irritates me that there are holes drilled in my frame that I have no intention of using. It's 2016 for crying out loud. What's with all the wires?