Should Muslim customs be judged differently from others due to security risks? Anyone can judge whoever and whatever they want. There is no official rule of the universe that tells anyone what they should and should not do. Everyone is free to judge or not to judge as they wish.
As to burkinis being banned in Cannes: If the residents or people-appointed politicians/representative vote to do so, then yes, the vote should be accepted and burkinis should be banned. Is it reasonable to ban burkinis solely for the reason of allegedly having links to Islamic terrorism? Probably not.
HOWEVER, I have been to the South of France, including Cannes, many times. During the summer months, the entire region receives a massive influx of tourists from the Middle East, most of which I assume are Muslim. I can personally attest to how several friends of mine and myself have received numerous dirty looks from Muslim men and women at the beach, presumably because we wore regular bikinis. Really?? YOU are going to come to MY country and give ME dirty looks for wearing what is considered completely normal beachwear in this part of the world?
Whenever I go to Dubai, I go out of my way, financially and time-wise, to make sure I am dressed appropriately, whether in the city or on the beach.
Just because your fashion is dictated by religion and my fashion is not, that does not mean I have to conform and you do not.
To dismiss the tenets of a particular faith on the grounds that some members of that faith are terrorists would render a great many Christian traditions to the wayside. No religion is without zealots and partisans, it is an inevitable part of faith. The more we persecute Muslims, the easier it is for the true terrorists to convert other members of the faith to fanaticism.
No, Muslims should not be judged differently due to terrorism. Judging Muslims differently has less to do with terrorism and more to do with scapegoating a minority. To compare Islam and Christianity, Christians tend to believe in modesty, chastity, and more conservative ideals. Christians are also quite likely to commit acts of terrorism, such as attacking abortion clinics. However, because Christianity is a majority religion in Europe and the Americas and Christians do not necessarily wear outer symbols of their faith, they are not targeted for religious discrimination like Muslims are. The ban on burkinis is, frankly, ridiculous: what do burkinis have to do with terrorism? Also, most terrorists are men, not women. Banning weapons at the beach or increasing security at tourist destinations would make sense, but targeting the burkini helps stop terrorism in no conceivable way. In fact, it only increases the hatred of ISIS for the West.
Muslims have the right to be treated fairly and equally and have the same religious freedoms as everyone else. They are no more likely to commit terrorism than anyone else, despite the idea of Jihad. In fact, statistics show they are actually less likely to be terrorists than other people.
Claiming that burkinis are somehow linked to terrorism is ridiculous. A burkini is just a swimsuit. The only effect that this could possibly have relating to terrorism is increasing terrorism. Muslims in France will see this as evidence of Islamophobia (which it is), and will only feel more ostracized, potentially leading some to become extremists.