I have just read your article on music in church. In it you state "...we cannot assume approval for something when none is given." How, then, can you use the Internet when obviously there is no approval to use it?
The line of reasoning is invalid. Instead of addressing the issue raised, you are trying to demonstrate an inconsistency in application. The goal is to say that if the my application is inconsistent then you are justified in also being inconsistent. This doesn't prove that the rule is right or wrong, it would only show that it is not being followed.
Imagine a child telling another child that he must obey his mother. "Well you took a cookie when mom said not to, so I get to stay up as late as I want!" The reasoning is false. It doesn't address whether mom should be listened to. It doesn't even tackle whether it was right to take a cookie. It tries to establish permission on an unrelated topic by saying they are similar violations. That is just not good reasoning.
However, in this case you are incorrect. "And Jesus came and spoke to them, saying, "All authority has been given to Me in heaven and on earth. Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age." Amen" (Matthew 28:18-20). The command to go and teach broadly covers numerous ways to teach. We see the apostles not only teaching in person, but they also wrote letters; therefore, writing is an approved way of teaching. The medium on which written communication is conveyed does not matter.
Therefore, the both argument you made and the way you were trying to prove your point are both wrong.