>Tremendously low interest rates coupled with quantitative easing dissuaded capital from financing the real economy and instead encouraged herding and levering up in the financial economy for returns.

This is the standard response that people repeat year after year. They are not the full or even major factor. They are more like a result of changes in economy.

>instead encouraged herding and levering up in the financial economy for returns.

Real reason:

Capital intensity has deceased dramatically. Capital intensity is the amount of fixed or real capital present in relation to other factors of production (especially labour).