Complex sentence: Some Gamergate supporters contended that their actions are driven by concern for ethics in videogame journalism, arguing that the close relationships between journalists and developers provide evidence of an unethical conspiracy among reviewers to focus on progressive social issues, leading to conflicts of interest.
Split into simpler sentences: Some Gamergate supporters contended that their actions are driven by concern for ethics in video game journalism. They argue that the close relationships between journalists and developers demonstrate a conspiracy among reviewers to focus on progressive social issues, leading to conflicts of interest.