The airspace was not exactly under Syria control at the time either, so claims of violating Syrian airspace sounds a bit strange considering all the US, French and other air activity over the country.
The difference being that the US, French and other air activity is not trying to shooting down Russian aircraft.
Like it or not but Syria has a sovereign government, Russia is there at their invite and it looks like Turkey launched a missile into Syrian airspace to destroy an aircraft that they knew was of no danger to Turkey itself. This was a political move to prevent Russia taking on Turkey's proxy fighters in Syria, and to prevent any knock on help being given to the Kurds. Turkey is certainly no paragon of virtue.
On a side note, Turkey is also probably miffed with Russia for pointing out and destroying the 1,000s of the Daesh oil tankers that were supplying Turkey with cheap oil.