They'll probably stop doing it when it stops seeming to be the case.
The actual standard, from In Re Walt Disney, is that business decisions aren’t reviewable unless “the exchange was so one-sided that no business person of ordinary, sound judgment could conclude that the corporation has received adequate consideration".
In, Shlensky v. Wrigley, the Chicago Cubs were sued for refusing to install lighting for nighttime games: their president believed baseball was best as “a daytime sport." This is absurdly nebulous (and kind of bizarre), but the Cubs nevertheless won. That decision was based on Davis v. Louisville Gas and Electric Co, which says “the directors are chosen to pass upon such questions and their judgment unless shown to be tainted with fraud is accepted as final. The judgment the directors of the corporation enjoys the benefit of a presumption that it was formed in good faith, and was designed to promote the best interests of the corporation they serve.”
While you can get sued for nearly anything, the legal standard is basically "Did you egregiously rip off the company so that you could make money?", not "Could you have squeezed ten cents more out of the public?"
the rule of wealth maximization for shareholders is
virtually impossible to enforce as a practical matter. The
rule is aspirational, except in odd cases. As long as
corporate directors and CEOs claim to be maximizing profits
for shareholders, they will be taken at their word, because
it is impossible to refute these corporate officials'
self-serving assertions about their motives.
— Jonathan Macey
Ford's response to the Dodge Brothers was:
My ambition is to employ still more men, to spread the
benefits of this industrial system to the greatest possible
number, to help them build up their lives and their homes.
Shlensky has a fairly similar fact pattern. The Cubs decision was supposedly driven by non-economic factors, namely beliefs about 'proper' baseball and possible effects on the neighborhood. However, they left open the door that these factors might themselves affect Cub's business prospects, a door that Ford slammed shut on himself. As a result, the Court found:
“Plaintiff in the instant case argues that the directors are
acting for reasons unrelated to the financial interest and
welfare of the Cubs. However, we are not satisfied that the
motives assigned to Philip K. Wrigley, and through him to the
other directors, are contrary to the best interests of the
corporation and the stockholders. For example, it appears to
us that the effect on the surrounding neighborhood might well
be considered by a director who was considering the patrons
who would or would not attend the games if the park were in a
poor neighborhood. Furthermore, the long run interest of the
corporation in its property value at Wrigley Field might
demand all efforts to keep the neighborhood from
deteriorating. By these thoughts we do not mean to say that
we have decided that the decision of the directors was a
correct one. That is beyond our jurisdiction and ability. We
are merely saying that the decision is one properly before
directors and the motives alleged in the amended complaint
showed no fraud, illegality or conflict of interest in their
making of that decision.”
It makes people scroll side to side to read the quote.
Please don't use code blocks for quotes.
And frankly, the fact that there's no other way to indicate a block quote is absurd.
In Ford v. Dodge, Ford was sitting on $60M, from which it had been paying dividends. These were stopped to reinvest the money in new factories. The Dodge brothers, who owned about 10% of Ford, sued because, per Ford's own comment, his decisions were driven by charitable interests rather than business judgement.
In Shlensky v. Wrigley, Shlensky was a stockholder who believed that the Cubs were leaving money on the table by not holding night games. He sued--and lost--because the Court found that to be a plausible business decision.
In Davis v. Louisville Gas Electric Co., Davis (or actually, his estate) held one type of share in the company, and opposed a reorganization plan that would have converted them to another, to his potential detriment.
In re Walt Disney was a derivative suit by shareholders over the hiring and firing of Michael Orvitz, and whether his (lucrative) compensation was in the company's interests.
The common theme is that the board of directors (and the CEO they appoint, etc) have wide latitude to run the company, even in ways that don't immediately benefit some (Davis) or even all (Shlensky) shareholders. They can certainly go too far (Ford) or fail to exercise much judgement at all (Caremark, where the director sold the company for a value plucked out of thin air), but as Mercantile Trading says "generally [...] courts will not upset the decisions of either directors or stockholders as to questions of policy and business management. An abundance of authority in other jurisdictions might be cited to the same effect"