No idea why you are thinking that.
Looking at whattomine.com there are still 6+ coins that are close to ETH mining profits.
And another 15 or so that will still generate some good money.
At a guess those will get crushed, but some others will probably come back up.
Monero and similar are my guess.
Not going to worry about it.
FYI there are dozens of similar posts about this very thing if you want to search a bit.
-Dave
Do you not know that every coin has something called difficulty which keeps the daily mineable supply capped. Right now since ETH is still mineable most GPU mineable coins have a similar profit per day.
Here is an example.
ETC has a daily supply of 100 ETC.
With 1 miner, he would make 100 ETC a day.
With 100 miners, each would make 1 ETC a day.
This is assuming each miner has an equal hashrate.
There are millions Of GPUs mining ETH right now. If they switch to ETC the difficulty will skyrocket and daily profits per miner will shrink by a huge magnitude.