Users send transactions to miners, miners send blocks to corporate node. Why not just have users send transactions to corporate node? Miners are only useful when there is no central authority. Once you stick in some sort of central authority, then there's no point in having miners.
As viperjbm and SgtSpike correctly stated, this is meant to be a PP competitor and therefore a business rather than a BTC competitor.
A business needs some kind of protection in order to stay alive and thus it needs to avoid people seeking to harm it. This centralization thing has been discussed many times around here but you are missing the point here:
Scenario #1: A new cryptocurrency (lets say FantasyCoin) is created from a group of people within the BTC community with the goal to get rich and they impose some kind of centralization when it comes to mining. This is definitely bad since their interest is to control miners.
Scenario #2: A new financial business (like RealCoin) is created from a group of investors that were not members of the BTC community with the goal to create a PP alternative. In this case, it is in the best interest of the business to protect its assets and therefore some kind of control has to be imposed ONLY to keep things rolling and to be able to offer a 100% safe service to the users avoiding bad miners.
As i have posted numerous times, although we believe that mining is an integral part of the system, i myself am not into mining (although i have educated myself over the past two months i still dont understand some parts of mining) and i can assure you that none of the investors is into mining as this is just not the point we are focusing on.
Therefore, we welcome the BTC community and its miners to earn tx fees in return for securing the network and helping with transactions from users.
The plan is to be fair to all miners. If you are a good helping miner then you dont have to worry about anything. This is just an extra layer of protection for the business nothing more than that and as said in the future it could be removed allowing for a completely decentralized service.