https://old.reddit.com/r/decred/comments/6wxueo/your_best_pi...
TLDR: Smart contracts on BTC were intentionally strangled because it would necessitate bigger blocks.
At the same time, BTC core devs were gearing up to start their sad push in creating artificial scarcity on a perfectly functional blockchain by reneging on the agreement they made to increase the block size.
They traded their ideals to get rich and all that momentum was lost. Instead of peer to peer cash, we're all left with a thousand useless ponzi schemes and a handful of promising coins that can't work together to actually achieve Satoshi's goal.