Why do people think just because you kick you know karate(even if you use boxing punches)?

The answer is simple. Most people are ignorant of what they see. They tend to use generic terms to describe what they see. In over 42 years I have seen many people call Judo, karate, or karate, Judo. People are generally ignorant and gullible about martial arts. They will parrot the ignorant comments their un-informed friends make. Ignorance, spread by the un-informed, only teaches ignorance. Correct teaching and experience can fix it. But, only if people what to be taught. Many would rather remain ignorant. Count yourself lucky that you know the difference.