I am disagree. I think bitcoin can be on the top without altcoins and all of them are weak competitors which not affect on bitcoin's price at all.
Bitcoin is created first and it doesnot need altcoins.
You're thinking is incorrect. Read my prior post in this thread, click the link I provided, and pay attention. You're going to learn some new things.
Altcoins are good competitors to Bitcoin and I think it just needs it.
Incorrect. Most of the speculation value from altcoins ends up in BTC, not in the altcoins. Altcoins are complementary to BTC. The reason BTC percentage of market cap is diving lately is because Bitcoiners are trying to force protocol changes to Bitcoin, instead of doing it on Litecoin, and so no progress is being made at all. Stuck in the mud.
Bitcoiners need to re-orient their thinking. Read my prior post and click the link and read more.