It's impossible to tell if GPU or ASIC mining will be completely unprofitable in the future.

Many people assumed that CPU mining was dead when there were GPU miners released for Bitcoin. Then other coins became CPU mineable.

Then it was assumed that GPU mining would be dead since ASICs came out and then Litecoin came out with Scrypt which was only possible to mine with GPUs.

Then Litecoin got ASICs and it was the entire cycle all over again with ETH.

So it's impossible to predict.