In the beginning a developer uses tabs in GWBasic and cries because they take up so much space.
Very soon after the developer uses spaces and engages in vigorous debate with his peers about whether to use 2, 3, or 4 them.
Then our developer realizes: “Hark! I shall use tabs for indentation and each shall be able to set the amount of space they consume to their liking. Verily the inventors of tabs were wise beyond their years.”
Our developer is a tireless advocate for tabs for they are flexible, lead to smaller files, and may be customized to your liking.
But there are still those who choose to use spaces, and yet worse, intermingle spaces and tabs! Although they do this unknowningly, it is a tiresome chore to continually clean the droolstains of others.
Finally, the developer reaches enlightenment and decrees: “There will be no more tabs in files on disk! No more will I clean the drool from other peoples chins, for those that insist on banging the spacebar and backspace key four times more than necessary shall be happy with their spaces and so shall I with my set tabstop=4; set softtabstop=4; set shiftwidth=4; set expandtab; or similar settings for the editor at hand, at least until elastic tabstops become standard.”
Spaces still suck, but not as much as this mess (pulled from fairly popular open source project file):