Why Did Corporations “Waste their Capital”?

Hi Roger,
I’ve got a basic question about how the post-2008 “economic fragility” you mention in your May 13 briefing relates to the “wasted” leveraged buybacks Raoul Pal talks about in the May 15th briefing:
Was the consumer too weak to support robust growth post-2008 and is that why corporations “wasted” their capital by buying back shares with borrowed money?
(21:06) RAOUL PAL: So I’ve talked about this in the doom loop on Real Vision before as part of a whole thesis of mine, which is based around the maximum amounts of corporate debt in US histories now. That debt was driven by corporations basically wasting their own capital to buy back their shares, without putting it to more effective use and efficient and productive use. 
What accounts for the use of buybacks rather than productive investments?
Why didn’t corporations use their capital for productive purposes?
(My suspicion is that consumers were too maxed out to afford substantially more consumption, so why invest in increased capacity?)
Here’s what you said about two days earlier about “economic fragility”:
ROGER HIRST: … That’s going to be what’s happening, and so it becomes all about balance sheets. It’s corporate balance sheets, it’s household balance sheets and it’s government balance sheets. Have they been impaired?07:16
I think the key to all of this is that there was the underlying fragility of the global economy prior to this. This was not a strong economy, and I’m not just talking about the last year where we saw some numbers deteriorate. I’m talking about the world post-crisis 2008 where there’s never proper recovery. We had anemic growth. We had the illusion of health because the equity market in particular and in particular in the US, rose to these astonishing heights, but overall, a lot of people, median wages took a long time– real median wages in the US took a long time to get back to the 2007 levels. I think it was ’15, ’16– 2015 and ‘16.07:52
The man on the street, the woman on the street didn’t see a pickup in wages for a long time. A lot of people are living paycheck to paycheck, 46% of Americans have less than $1000 of cash in their savings account.
Did corporations think that their consumers were too maxed out to generate further growth in 2009 – 2020?
In other words, did they view their customer’s balance sheets and income growth potential so dimly post-2008 that they decided productive investments in additional capacity, etc were too risky and that it would be safer to take advantage of low-interest rates to use debt to buy back their own stock?
I understand interest rates were low and executives were looking to meet their bonus targets, but why did that entail so many share buybacks rather than productive investments?
I figure the pros may already understand that this has taken place, but as a “citizen investor” I’d appreciate hearing this spelled out more explicitly.
If corporations were reluctant to invest before, what does that say going forward?