Sure, until miners decide to point their gear to another coin. Remember, reward halving means miners will gross half as much as they do now. Depending on BTC price at that time, their net could become negative.
There aren't very many alternative coins that a Bitcoin ASIC could mine. And even fewer that are actually worth anything.
There's nothing worth mining now because it's hard to compete with BTC at its current block reward. This may all change next year if BTC price doesn't double by the time block reward is halved.
The whole thing kinda feeds on itself, think
the kindling model. Bitcoin is strong because it's strong; because a large, expensive network of miners is behind it. Turn that network to a clone coin, and bitcoin's no longer strong, the clone coin is.