The optimist in me would like to believe that Delta took this risk, because they considered their humanitarian mission more important that the mechanical integrity of one plane. I would encourage each and every company I own stocks in, to prioritize their goals similarly.

Every situation is going to look different. But if I found out a company I was invested in had an opportunity to save lives at a reasonable risk[1] and chose not to due to concerns about whiny shareholders and PR, I'd dump them and write comments about their shitty morals on message boards.

[1] Whatever that means. And I have no personal opinion about the risk involved in what Delta did, because I'm not qualified to form one.

Edited to add: it is nice to be able to applaud an airline for a change. Yay, Delta.

Given that lives were not in fact at significant risk, it's conceivable to me that they considered the amount of free publicity this would likely get. Given that, and the relatively small chance of serious damage or loss of the plane, and it could be a decision with positive financial expected value.

Plus, of course, there is the humanitarian benefit.

As explained by omegant in the post above, lives were not at risk here.

The risk was to the aircraft: if it had been delayed on the ground at SJU for any reason, it might not have be able to depart before the storm hit and would likely have suffered severe damage.

Normally I would think that

> hundreds of millions of dollars in my rolling stock

would refer to the aircraft ... except that's a nearly 1-order-of-magnitude overestimate of it's value (a single $100M, not multiple).