Alonso's nationality is irrelevant when trying to explain his behaviour. It is only relevant when trying to explain the behaviour of the press and the fans from particular countries.
I find it very difficult to find any evidence whatsoever that Alonso was treated anything less than equally with Hamilton certainly before Hungary and even afterwards. When pushed, even Alonso denies he has been handicapped compared to Hamilton.
The problem is that Alonso feels that he has been treated equally with Hamilton and that should not be the case for a two times world champion driving alongside a rookie. He felt he should have received preferential treatment. This would not have been a problem if Hamilton had been slow, but he was not. We know from his days at Renault that Alonso could not cope with being beaten by his teammate. In those days his teammate was Fisichella so those days were rare, but this season Hamilton was regularly as quick as or quicker than him, compounding the frustration.
Had Alonso been accusing a team with a strong past history of favouritism like Renault or Ferrari then the paddock would have believed him (NOT the fans, the paddock). Unfortunately he accused McLaren with its strong reputation within the paddock and once the story of attempted blackmail came out his reputation was ruined.
As someone who supported Alonso coming into this season I'm quite bitterly disappointed by his behaviour and he has done himself no favours. Before this season just about every team on the grid would have welcomed him, now people will be having second thoughts about signing him.