Who knows. Some people need to feel secure and have to feel they are right, even if it means trying to get everyone else to agree.
Sort of like religions. Either you believe in my god(s) or you will go to hell. In that case, everyone goes to hell because no one believes in the same god(s).
Not trying to start a holy war here, so lets kill the flame before it becomes a war.
I still think someone is trying to troll the place, just to waste energy on discussion an issue that doesn't exist, or at least well-known. Could be an... anomaly.
For such issue, the OP would need to do an exchange and get a new unit and play with it. Even if it means all the demo units in store are "like that". Just get a replacement and see if it really improves. Over an internet forum, it's hard to tell if one person's expectation is different than another, or many other reasons. It could be that a 0.5s loading time to some people means fast. To another person, it's too slow for them, they want instant gratification, like they have been used to on their quad-core machine.
Even if it's just your imagination, if you feel this isn't for you, return it, and get what you like instead. Perhaps a rMBP. I have both and I like them both.