There is a difference between a design decision reasonable people can disagree, even forcefully, about, and a design decision that is actually a deceptive attempt to get people to buy new hardware.

They spelled out the reasoning in the post:

“in order to support the increased cryptographic loads that we see as part of pfSense verison 2.5, pfSense Community Edition version 2.5 will include a requirement that the CPU supports AES-NI”

You may disagree with that but it's intellectually dishonest to argue as if they didn't provide clear, technically defensible rationale, especially at a time when much of the industry has been moving to hardware offload.