The poem & my sentiments about it ...

Tyger Tyger, burning bright,
In the forests of the night;
What immortal hand or eye,
Could frame thy fearful symmetry?

In what distant deeps or skies.
Burnt the fire of thine eyes?
On what wings dare he aspire?
What the hand, dare seize the fire?

And what shoulder, & what art,
Could twist the sinews of thy heart?
And when thy heart began to beat,
What dread hand? & what dread feet?

What the hammer? what the chain,
In what furnace was thy brain?
What the anvil? what dead grasp,
Dare it's deadly terrors clasp!

When the stars threw down their spears
And water'd heaven with their tears:
Did he smile his work to see?
Did he who make the lamb make thee?

Tyger Tyger, burning bright,
In the forests of the night;
What immortal hand or eye,
Dare frame thy fearful symmetry?

This poem completely contradicts Bruno Heller's sentiments about the Red John character. It absolutely points to an unknown entity that has not yet been fully shown to us the audience. 

"These people, serial killers ... they are just people. They are not special and to glorify them is not what this show is about"

The poem glorifies the tiger 100% without question. The tiger is beautiful, majestic, glorious and yet it has a horrific capacity for violence & darkness. That is the symmetry: equal beauty & horror. 
All work reflects the creator in some way and so the poem asks ... what does such a creation say about the creator? What kind of divine being (immortal hand) could have the capacity to "twist the sinews of thy heart" in such a being? What kind of divine being could have created such beauty and yet such horror. "Did he smile his work to see?"

This poem must have been chosen deliberately before the first episode ...

I cannot understand why this poem was chosen if it was to represent Sheriff Thomas McAllister ... if it was chosen to represent someone who runs and begs for their life ... someone who's opinion of them self has been inflated and is not particularly beautiful and yet horrifically violent and dark.

Tigers do not run. Tigers do not beg for their life. Tigers do not have inflated opinions of themselves. 

Whoever ... whatever this poem was meant to represent ... we are unaware of it/him/her. You don't inspire a show from a beautiful poem and give not only a week representation of it but a contradictory one. Especially after you glorified Red John for six and a half seasons ... 

Unless Bruno Heller's intent was to quite literally show a man with "delusions of grandeur" who was in fact a pathetic normal person whom did not have the power he assumed in himself, who did not have "real psychic powers" ... unless the poem was meant to represent inflated ego and vanity which is a poor representation of the poem ... then we do not yet know the real Tyger.

I personally love the show regardless and in any case.