Of course you should. With the exception of sociopaths or people raised by wolves, it should be second nature to be nice/respectful to others.

I say hi and "thank you" to the fellow who empties my trash can at work every night because he's another human being, not because I think he can advance my career somehow.

I think the speaker in the video is just reminding us that being nice has concrete benefits sometimes.

Do you know everything about who you are not showing respect to? Do you know if or how they might benefit/hurt you later? It's easy to work from assumptions and completely misunderstand the situation.

Should have been more clear: this is sarcasm. The guy in the video sounded like a douche.