Because it implements the moral ideal of self-sacrifice to the needy.

WSJ: Is Rand Relevant?

The new law exempts employee contributions from the 25% of earnings limit applied to employer contributions, making a 401(k) ideal for a self-employed person who doesn't earn a lot, but can save a lot.

FORBES: Self-Employment

Advancing the ideal of democracy and self-government is the mission that created our nation and now it is the calling of a new generation of Americans.

NPR: Bush Reaffirms Iraq Strategy

The ideal candidate would be a self-made billionaire who voted for Obama (and who may still like the man) but is now appalled at Obamanomics and willing to say so.

FORBES: Two-Front War Against Obamanomics

Self-cleaning clothes would be ideal for people who don't have time to wash their clothes or don't have the facilities to do so, he believed.

CNN: Washing no longer dirty work

New Yorkers love to tease that Brooklyn is ideal for young people who love ironic eyewear, self-employment and a closet full of skinny jeans.

BBC: Brooklyn: The Wall Street alternative

In other words, I might answer a survey as if I were an ideal version of myself rather than reflecting a true self-analysis.

FORBES: Men Choosing Fatherhood Over Careers

The ideal person would still seem to be someone with composure, a self-controlled specimen of high esteem.

FORBES: Millenials Must Stop Advertising Their Insecurity And Incompetence