Another false flag. We don't know about the true identity of the attacker. And from the slogans which he shouted before the attack, I believe that he is also from an Islamic background. And from the article, it is clear that the perpetrator suffered from acute schizophrenia. So it seems that the attack resulted from mental illness, rather than Islamophobia.
I'm sorry but what you are stating here is wrong, As a French and since this case was big, it was impossible to miss any information about it, it was clearly an islamophobic attack. Also According to officiel and several organisation (in France), Islamophobia cases has skyrocketed after the Terrorist attack on Charlie Hebdo I can list some if you want (there was an increase in antisemite act last year as well but that's another story).
The other which I mentioned before is what you are exactly stating above ie Every attack done on a muslim is related to mental issues, but when it's a muslim doing them it's automatically terrorism which stupid. you don't believe that every cases done against any muslim is related to mental issue and excusable and statically it's impossible.
Muslims are at war with non-muslims. Where there is such group pride and group identity, there is collective retribution.
You made your bed. Now sleep in it.