might be a little tl;dr but none of this is a problem actually
i've had the same problem with my bitcoin miners, which i knew was going to happen eventually anyways. they used to be making me a few hundred worth of bitcoin a day, now they're reaching the point where the few dollars they make barely outweigh the cost of electricity. will be turning them off next week probably.
it's decent read i guess, but he bases a lot of it off some flawed premises, like the idea that the lost profitability is due to the drop in bitcoin price from 1200 in december (which was obviously going to be corrected anyways, no one thought that was going to last). the bitcoin price has "bubbled" and crashed 4 times in the past, and it's due to happen again in june/july if it follows the trend of the past four bubbles/crashes (and by the end of the crash, the value is still greater than at the beginning of the bubble)
what affected the profitability of miners to a far greater extent is simply that the bitcoin mining algorithm changes the difficulty of the math problem these machines have to do over time as the mining network increases.
so the fact that profitability decreases for old machines is a sign that there's actually a much greater amount of hashing/computing power invested in the network than ever before (which is a great thing, because it means the network is more secure and its exponentially more difficult for a single party to attack the network). and the ultimate beauty of the mining algorithm is that if it ever becomes so unprofitable to mine bitcoin that people stop doing it, the difficulty will decrease on its own in order to adjust and once again make it profitable.
as the chart shows, bitcoin network hashing power has been growing exponentially VERY steadily, refuting the idea that miners are leaving in droves to mine other coins (which they cant anyways, since bitcoin mining machines use a different hashing algorithm than altcoins, so you need to buy a whole new miner if you want to mine something like litecoin)
this whole phenomenon was predicted very early on, as early back as in the original whitepaper written by satoshi nakamoto where he basically invented the entire protocol. he realized that in the future, mining will no longer be feasible for the average person at home, and eventually mining will be done by a smaller number of parties with big farms of mining rigs. as long as none of these individual parties reach 51% of the total power, that's totally and completely fine. (and if they do reach 51%, there's measures that can be taken to avoid that as well)
the last big point the article makes is that it leads the smaller players in the mining game to start mining alt-coins instead and that will cause. the author acts like this is a problem because it inflates the monetary base, but only among the particular alt currencies which no one really uses anyways besides for speculation (90% of them are essentially scams where the creators have premined 50% of them, and then once the price increases a little bit after hyping them up to the general public, they dump their 50% and make a profit, meanwhile killing the coin by flooding the supply). it's like saying that the ridiculous inflation of the zimbabwean dollar would somehow have a negative effect on the US dollar
