There was a very important reason that the humans on Earth and the Federal Parliament were willing to accept the Protoss, forking over property and capital and allowing them to land their ships and settle on Earth.
Earth was, in fact, the native homeland of the Protoss.
The language spoken by the Protoss was more than 50% similar to Chinese, including their accent. The script used by the Protoss was an improved system traceable back to the oracle bone inscriptions. It was a type of ideogram and had many similarities with Chinese characters.
Hence, the Protoss' culture was derived from an original common origin. They could not be considered aliens.
Taking into account this important factor, more than 30% of people had a welcoming attitude regarding the return of the Protoss and did not discriminate against them in their hearts.
