Why does it take so long? Follow the money. There are only and handful of lawyers who represent death row inmates. Paid for by the taxpayers.
My favorite case was when the defense attorneys made a last ditch attempt to save their client from the death penalty. Their final appeal was "ineffective representation". They were such bad lawyers, they couldn't save their client. This appeal was kicked out/laughed out of court. Of course neither of these lawyers turned in their sheepskin when their client got his just reward.
"No man's life, liberty, or property is safe, while Congress is in session." Mark Twain