Why is Tybalt not to blame for Romeo and Juliet's deaths?

Tybalt is not to blame because he was just doing what his elders taught him to do. 

If I have to pick a single character to blame for the deaths of Romeo and Juliet, it would be the friar; therefore, I can't blame Tybalt. Friar Lawrence agrees to marry Romeo and Juliet with the hope that the wedding will end the long-standing feud between the Capulets and Montagues.  

But come, young waverer, come, go...

Tybalt is not to blame because he was just doing what his elders taught him to do. 

If I have to pick a single character to blame for the deaths of Romeo and Juliet, it would be the friar; therefore, I can't blame Tybalt. Friar Lawrence agrees to marry Romeo and Juliet with the hope that the wedding will end the long-standing feud between the Capulets and Montagues.  

But come, young waverer, come, go with me, 
In one respect I'll thy assistant be; 
For this alliance may so happy prove, 
To turn your households' rancour to pure love.

Romeo and Juliet both commit suicide, so I do believe they deserve the most blame. The nurse deserves some blame too, since she helped arrange meeting times for Romeo and Juliet.  

I suppose it is possible to blame Tybalt in some way for Romeo and Juliet's deaths. Tybalt is an angry and quick-tempered guy. He is angry Romeo is at the ball, and he vows revenge. Romeo won't fight Tybalt, so Tybalt and Mercutio fight. Mercutio dies, prompting Romeo to fight Tybalt. Romeo kills Tybalt and is banished as a result. Juliet is sad. Lord Capulet tries to cheer her up by attempting to force her to marry Paris. Juliet takes drastic measures not to marry Paris, and Romeo and Juliet wind up dead. If Tybalt hadn't been angry about Romeo being at the ball, then the rest of the events wouldn't have happened.  

That's how Tybalt could be blamed, but I think that is a stretch. Tybalt is angry at Romeo's presence because Romeo is a Montague. Tybalt has been taught from an early age to hate all Montagues. Who taught him that? The Capulets. Had Tybalt not been influenced to hate all Montagues, he would not have been offended and angered by Romeo's presence. Tybalt is not to blame because he only acted in the way he was taught to act by the older Capulets.