What are the arguments for and against deprecating transaction priority? A recent pull request moves ahead to deprecate the concept of transaction priority by changing the block priority space to zero. This has enraged some users who believe that deprecating transaction priority means that it will no longer be possible to create zero fee transactions. 

So what are the arguments for and against deprecating transaction priority?
Since transaction priority has never really been a consensus based "protocol", it was never really that valuable to have it in the core code. Miners can and DO change the priority how they see fit. I see it as less code to maintain in the end and since Bitcoin is meant to be a free market network, the fees paid will prevail