It's not possible in my opinion that BTC will completely lose its entire value, it's here to stay and has proved already that it has great potential. Altcoins have to thank Bitcoin for showing the way, and lately we are seeing BTC and other altcoins moving along (before it was usually contrasting, when BTC was going up ETH was going down and vice versa) but the more dominance BTC has over the market the more it affects its entire performance. So when we'll see BTC gaining back a market dominance of about 60% then we'll see the market reacting more to how it's performing. Unfotunately if Bitcoin will fail, which won't happen, it will take the rest of the coins with it, but eventually people will realize that it doesn't make sense to follow bitcoin, as each technology is different, and the market will again adjust.