They're not, and it's rotton for a number of reasons for me to throw shade on people who choose to be parents, even for the sake of "argument" (read: discussion).
My point, if I have one, is that it's just as hurtful to be called selfish for choosing to remain childless as it is to be labeled a breeder for choosing to have children. I also think both positions are as debasing to the people espousing them as they are to the people to whom they're directed. Both are condescending, scornful and unnecessarily judgemental, and neither serves any constructive purpose.
I'm a tit-for-tat kind of chum (or perhaps just tit), so when presented with the option to turn the other cheek, I typically opt to take a mobster apporach of based one-upsmanship. To wit, when I hear someone say "not having kids in selfish", I fall over myself to riposte the assertion.
I could expound my personal position, but it would be heavily prefaced with "but that's just me, I don't begrudge anyone their choices, no one should feel bad for doing what they believe is best, etc." Essentially the exact opposite of what's depicted in this meme.