I'll attempt to analyze a couple of different perspectives.
1. It is artificial
Synonyms: insincere, feigned, false.
There is the idea that any "intelligence" created by humanity is not actually intelligent and, by definition, it is not possible. If you look at the structure of the human brain and compare it to anything humans have created thus far, none of the computers come close to the power of the brain. Sure they can hold data, or recognize images, but they cannot do everything the human brain can do as fast as the brain can do it with as little space as the brain occupies.
Hypothetically if a computer could do that, how do we determine its intelligence? The word artificial defines that the intelligence is not sincere or real. This means that even if humanity creates something that appears intelligent, it has simply become more complex. It is a better fake, but it is still fake. Any money not printed by the government is by definition counterfeit. Even if someone finds a way to make an exact duplicate, that doesn't mean that the money is legal tender.
2. Misuse of power
If an AI is given rights and chooses to exercise those rights in a way that agrees with its creator's views, possibly through loyalty to its creator, or through hidden motives, then anyone with the capabilities to create such an AI would become extremely powerful by advancing their own beliefs through the creation of more AIs. This might also lead to the ruthless parallelization that you mentioned, but with (even more) selfish goals in mind.
If this were not the case, and an AI could be created to be neutral with free will and uncontrollable by humans, then perhaps an AI could be given rights. But I do not believe this would ever be the case. With great power comes great responsibility. Even with free will, a true AI would most likely end up serving humanity, because humans have control of the plugs and the electricity, the Internet, the software, and the hardware. The social implications of this for the AI are not promising. It's not even just the ongoing control of these resources that is the issue. Whoever creates the software and hardware for the AI would have special knowledge. If fine adjustments were made, specific individuals would undoubtedly hold sole control of the AI, as adjustments could be made to the code in such a way that the AI behaves the same except under specific circumstances, and then when something goes wrong (assuming the AI has its own rights), then the AI would be blamed rather than the programmers who were responsible.
In order for humanity to get away from anthropocentrism, we would have to become less selfish when it comes to humans, first. Until we can solve every existing social problem within humanity, there is no reason to believe that we could cease thinking of humanity as more important than created machines. After all, supposing there were an almighty God that created humanity, wouldn't the humans always be beneath God, never to be equals? We can't fully understand our own biology. If an AI were created, would it be able to understand its makings in the same way its creators would? Being the creator would give humanity a sense of megalomania. I do not think that we would relinquish our dominion over our own technological creations. That is as unlikely to happen as the wealthiest of humanity willingly giving the entirety of their money, power, and assets to the poorest of humanity. Greed prevents it.
4. Post-human fundamentalism
Humans worship technology with their attention, their time, and their culture. Some movies show technologically advanced robots suppressing mankind to the point of near-extinction. If this were the case and humanity were in danger of being surpassed by its technology, humanity would not stand idly and watch its extinction at the hands of its creation. Though people may believe superior technology could be created, in the event we reached such a point humanity would fight to prove the opposite, as our survival instincts would take over.
5. A balance?
Personally, I do not think the technology itself it actually possible, though people may be deceived into thinking such an accomplishment has been achieved. If the technology were completed, I still think that anthropocentrism will always lead, because if humanity is the creator, humanity will do its best to ensure it retains control of all technological resources, not simply due to fear of being made obsolete, but also because absolute power corrupts absolutely. Humanity does not have a good historical record when it comes to morality. There is always a poor class of people. If wealth were distributed equally, some people would become lazy. There is always injustice somewhere in the world, and until we can fix it (I think we cannot), then we will never be able to handle the creation of true AI. I hope and think that it will never be created.