There is no problem with ypool having 70% of the hash power because they are very limited in what they can do with that hash power. They can do a Denial of Service or they can attempt a double spend...
...
Consider this a case study in the reality that the 51% attack is not really a concern.
Are you completely out of your mind?
Yet here you are, lead developer of a company who wrote decentralization all over its awful designed websites. You fail to deliver on your own invention stating the day it should be released that Poland was too slow. And now you say Oh its cool that people just use one pool... This will kill all other pools leaving PTS to 100% to ypool making it the bottleneck of a coin that was supposed to be a share of future Decentralized Autonomous Corporations, promoted by a company that screams Decentralization but actually does not give a fuck about it.
Tomorrow i will get complaints by my neighbours for the loud noise emitted by this epic facepalm.
My point is that whether they can control 51 or 100% or not is irrelevant to the security of the coins. If they start performing a DOS attack on the network then miners will leave and join a new pool. But ypool has no financial incentive to attack and mining pools cannot perform double spend attacks because every block they work on is public record which means they cannot 'mine in secret' and thus there can be no alternative chains.
True decentralization is competition and lowering the barriers to entry.
While I am a proponent of decentralization, I refuse to pretend that bitcoin, mining, etc are decentralized when they are not. Instead I will focus on the true innovations that free us all:
"Irreversible, Unforgeable Global Ledgers"
If you have such a ledger that is distributed far and wide then it does not matter what any one bad actor does.