It's important for us, all the people who play Arma 3, because this engine limitation don't let people use the full potential of their hardware. This seriously hits the performance and makes the game run horribly on almost every single system (especially in multiplayer), no matter which specifications you have! It's more than a year now since Alpha and the issue remains unsolved (you may check ticket about it here http://feedback.arma3.com/view.php?id=716 ). In fact even partially, yet there is still no any news from developers about this issue is actually being actively worked on. Majority of people in community are starting to be highly doubt about this issue to ever become solved. Instead of this major issue being solved first, we all see DLCs like Karts, Helicopters and Marksmen are being released!

Bohemia, needs to prioritize this issue over everything else they are working on! Sure thing there are tons of more bugs, but this is so far that should be the most important issue with this game, as it simply affects the way it runs to absolutely unacceptable!

Two videos by NyaGaming explaining the issue

Video 1​

Video 2

Just wanted to add that developers are well aware of poor CPU usage since Arma II times and in my humble opinion, if a reasonable developer would care about proper optimization of the engine, they would put this task to be fixed on the first place, even more, a reasonable developer would never go for releasing the Arma III Alpha before this issues is solved.