Why not just one coin? Divided over 1 million billion cents. This whole thing is pretty much irrelevant, but then again, most altcoins are anyway.
Are they irrelevant?
Which ones?
All bitcoin straight forks are irrelevant. Bitcoin is still very far away from mainstream, and the alt coin section is even lower. You see sites like Namecheap and Reddit accepting bitcoin, but not litecoin or another flavor of the day.