Is this a joke? You should be wary of Prague and Rome too then. Welcome to the Europeean Union of Mooslims
I don't blame people for being a little ignorant and scared. Turkey = Muslim so therefore a lot of negative connotations may be brought up in their heads (thanks world news media).
But the reality is...and I don't mean to sound racist...Istanbul is mostly a white city. The majority of the population are racially white caucasian with varying skin tones. Some people are religious, most are not, and even the ones that are don't tend to be threatening. So what I'm saying is, would you feel frightened in any other European city? (I'm assuming you're white).
Istanbul has all the Western brands, shopping centres, family life, restaurants, sports clubs, cafes, drinking spots, nightclubs, etc. etc. anything you can think of existing in a Western country exists there and the population are like Western people.
It's a 1200 km drive from Istanbul to the Syrian border. I think you'll be fine.
This is a good point to bring up. Los Angeles is probably closer to danger zones of Mexico than Istanbul is to ISIS controlled Syria. Turkey is a huge country, if you count it as a European country it would be 2nd only to Russia.