Alterna-coins are a natural outgrowth of bitcoin introducing a new idea into the ideasphere; the fact that it is open source makes cloning the idea trivial. Alterna-coins were always inevitable.
If someone can come up with a better bitcoin than bitcoin -- that's great! Humanity benefits from the competition.
Speaking as a developer, though, contributing patches back upstream would be nice
I've sent a few patches upstream. Well, here's one more:https://github.com/bitcoin/bitcoin/pull/1536
Litecoin was attacked with dust spam where the attacker would send a transaction with thousands of outputs of a satoshi each. Yet, they only get charged the base fee. This fixes it by making the fee grow linearly with number of dust spam.