The 15" retina MBP is 220 ppi, and the 13" is 226. The iPad 4/iPad air is 264 ppi, and the iphone 5/5S are 326 ppi. I can see the pixels on my iPad 4 if I look not too hard, so I'm curious how much lower can you go before it's not retina? 226 on my wife's incoming 13" rMBP seems like it's actually pretty low.
Apple have never claimed that in Retina displays you can't see the pixels. They claim you can't see the pixels from a normal viewing distance, defined by Apple.
PPI is only one part of the "Retina Display" equation. You have to consider the viewing distance as well. You're simply comparing PPIs of different devices. You would not be viewing a MacBook Pro screen at anywhere close to the distance you would an iPad screen. This is why the iPhone, a device you hold much closer to your face than an iPad or MacBook, needs a higher PPI to be "Retina." The average person won't be able to discern the pixels. The fact that you can at assumingly a normal viewing distance suggests that your vision is better. You are an outlier. (You aren't placing your eyeball right on the iPad screen when you say that you can see the pixels, are you?)
Its not the retinaist of the retina displays, but that doesn't mean its not retina and your eye can discern them as you can't already discern the lower resolution retina to begin with... unless you use the devices really.. really... close, which is bad for your eyes anyways, dont do it.