I agree it was poor taste to compare the slaughter of animals to those of people, but perhaps they were trying to humanise the food animals. It's understandable why they felt they needed to but they just don't realize that most people don't see it as they do. Extremism usually creates division, not a meeting of the minds.
Keep in mind that although some think of PETA as being a bit extreme, let's not confuse them with the fanatical, violent extremist organization like the KKK. The KKK would like nothing better to eliminate certain peoples whether it be by politics or violence.
Peta wants to stop what they see as violence towards animals.
As long as they don't turn to violence, I won't object to their organization.