Disney's mind is made up, and they have never reversed a decision based on a petition, AFAIK. Streets of America is disappearing to make room for Star Wars land. There is no comparable spot for it to go. SOA worked because it served no purpose the rest of the year, and had very low traffic. So erecting and taking down the lights was quite easy. And since it wasn't a thoroughfare, the massive crowds at night did not inhibit traffic to other attractions, restaurants and shops.
There is no other street in WDW with similar facades AND NEXT TO NO FOOT TRAFFIC. Putting it anywhere else would result in a nightmare of congestion.
Sign as many petitions and write as many letters as you want, but your resistance is futile.