People forget that Satoshi was at least mildly supportive of an idea like bitdns/namecoin with his biggest issue making sure it did not compete with bitcoin for hash. I believe he may have sparked the idea of merged mining in this discussion.

99%+ alts are not worth the time. They either make tradeoffs that are not great, or don't do anything useful enough to be distinguished from bitcoin.

There are a few that are useful and have tradeoffs that are worth the trouble.