He makes a pretty poor case. His examples include:
Tintin wearing a kilt in "Black Island";
his telling Haddock to promise to stop drinking when they first meet in "Golden Claws" and how Haddock breaks down thinking about his mother (as if Tintin's supposed femininity has reminded him of her);
the unicorn of "Secret of the Unicorn" is a "feminine and phallic symbol";
the way Tintin apologises rather than gloats when the bully smashes his fist into a wall in "Prisoners of the Sun";
on the cover of "Castafiore Emerald", when Tintin puts his finger to his lips, Cespedes interprets that as a reference to the "family jewels": Castafiore is a Castrato - a man who was castrated in order to preserve the soprano or contralto range of his voice;
and in "Picaros" we have soldiers dressing up as carnival transvestites. Curiously he states that it is Haddock who encourages this idea, whereas it is in fact Tintin who puts it to Alcazar.
I imagine that if I, an Englishman, were to tell the Scots that kilts were an example of their femininity it would be the best case ever for independence! I wore one at a wedding last year and quite enjoyed it - and, before you ask, I did wear underwear as well!
I tend to agree with some of the comments on the Independent page
that Cespedes is simply after his 15 minutes of fame. For a self-proclaimed philosopher he could come up with something more constructive.