Part of what makes us whole as humans is the love that we feel even from the womb. Studies show that children are more healthy, smarter, and have a higher thrive rate when they are sung to, read to, talked to. How then can we hope to have success in a test tube, sterile environment?
I do think that cloning will lead to unethical eugenics movement, but that does not mean that cloning should be stopped. With any new advancement there are going to be people who are taking advantage of the technology. It is a risk we have to take in order to gain the benefits of new technology.
The president William Clinton decided that cloning humans was unethical. At the time the research was that it was possible to completely clone sheep. While this could lead to cloning human for reproductive purposes, the only benefits draw eerily close to producing a so-called "master race", and while that may seem racist, it is not, but is still immoral.
Without a doubt, cloning would ultimately turn into an unethical eugenics movement. Cloning would allow unscrupulous people to genetically modify human beings in new ways. That would undoubtedly lead to ethics violations and other issues that we might not even be aware of, so human reproductive cloning is a bad idea.
The special thing about humans is our flaws are unique and what makes us a person. Cloning could lead to the same exact person with the same qualities. Let people be individuals not what society sees as beautiful or perfect. Everyone is perfect for their imperfections that they currently have.
As we know from Dolly the sheep, cloning is an imperfect science. To clone a human, you are dooming it to shortened lives. Eugenics does not need cloning to be done. People donate sperm and eggs all the time. All they need is someone to carry a genetically modified human. Someone would do that for the right amount of money.
Cloning just copies an individual's DNA. You're thinking of gene therapy. Cloning by definition involves no genetic modification. Hypothetically you could start with a clone and then make a few modifications, but to what ever extent the clone is modified the clone is no longer a pure clone.
As for gene therapy it has the potential to make people healthier, curing diseases, and expanding people's choices in life by improving freedom through expanding people's abilities (better abilities means more choices, people are more likely to be able to live the life they choose to live). How in the world can that be unethical? I understand the concern about social inequality which is why I think this technology should be available to everyone for free once fully developed and tested. If that turns out to be way too expensive then it should at least be subsidized.
If human cloning becomes a mainstream movement, scientists and the government will regulate advances appropriately. Genes can be altered at the early stages of development to try to create a "better" human being (a la Khan Noonien Singh of "Star Trek" fame). However, a "eugenics movement" won't happen because it will take several decades after cloning is perfected to make it cheap enough for the common man to have altered DNA in clones. A eugenics movement may start, but it won't be unethical because consumers will demand it once cloning becomes the norm.
Cloning will not lead to an unethical eugenics movement. This is because of the fact that eugenics is not inherently unethical. There is a small chance that there would be an unethical eugenics movement if cloning were to occur on a mass scale, but a much larger one that it will be an ethical one.