LINUX systems are around 2-3% of world market.. so writing malware for LINUX is not as profitable as for WINDOWS or MAC's
Oddly enough WANNACRY malware striking the world now.. was written for WINDOWS systems only.
It is also how comfortable are you with computers.. I run no anti mal systems. I am comfortable talking to my computer. It's free! It's fast. 90% of the worlds fastest systems run linux platforms..