I like a technology (including programming language) but its platform is closed sourece and many times I meet people who ask me, why do you use a closed source platform, why not use an open source alternative? If there is something wrong it should be with the closed source not with the open source, (as they say). Actually I don't know how to answer their question.Could anyone tell me a good answer? Why do you use a closed source platform? 
What are some reasonable arguments in favor of closed source software? 
open source;closed source