There are several aspects to consider, but is likely to be profitable forever.
Just two out of many:
- ASIC miner companies price per GH/s is based on BTC market price.( Which is abusive practice IMO ) That's why they sell it to you instead of mining, they decide how much you may profit if anything at all. The actual manufacturing cost is very low in comparison to street price, so there is a big margin to be reduced.
- Difficult should adjust with people giving up.
PoW cryptocurrencies cannot rely on a decrease in hashrate to increase mining profitability because the security of the network is derived from the hashrate.