There have been a lot of other alt currencies, but don't seem to have what Bitcoin does. I think down the road potentially, but as of now the focus seems to be on how to make Bitcoin better, safer and more accessible. We're pretty bullish on it.
They can't be bitcoin if bitcoin will be died and it will never replace by other cryptocurrencies because i think that bitcoin is the father of all alternative coins if theres no bitcoin it will be worthless for those altcoins. Bitcoin is good and very expensive to be change 
This discussion has nothing to do about being the father of all cryptocurrency, but the usage and effectiveness of Bitcoin with regards to economic and technical use.
I think at this time there is no other currency yet that surpasses bitcoin effectiveness in economic scale. Thought I believe in terms of technology, there is far better currency that bitcoin but popularity and economic wise there is none that will make bitcoin obsolete at this time. The possibility is still there but when is still unknown.