I think being an Anglo on an Anglo message board has hurt him because he’s been hyped by anglos every single year. As Angliru mentioned, Anglo coverage put him in the same status as Froome, Contador, Nibali, Valverde, and Nairo every single year when his palmares resembles Fuglsang, who had never been seriously considered a Tour contender until the last year when Froome and Dumoulin were out with injury. Now Fuglsang is a hell of a rider, as is Porte, but neither have a record that should put them on the same level as multi GT winners like Froome, Nibali, Contador, or Nairo- multi GT winners, or Valverde who has multiple Top 5 finishes as well as a a GT before a GT starts.
Plus: for many forum members who have been around since the beginning, he probably suffers in popularity due to the over the top hype Evans received before his TdF win from certain Aussie fans. Unlike Evans, Porte seems unlikely to have more opportunities to win over his critics by winning a big one.