The main point you forget about bitcoin is that it is not controlled by any one and it is accepted by 99% of the crypto world. Majority of coins are valued through btc. The Altcoin which you are telling is controlled by their developer and if the developer abandon their project then automatically the coin value can go to zero also. But in btc case value going to zero is nill to possible as it is accepted by everyone and it is not controlled by anyone.