The simple answer is; flexibility. By definition, columns are just inline blocks - it's the way CSS columns are supposed to work. Creating CSS columns by applying inline-block opens up a whole world of flexibility for your columns - the most useful benefit being the ability to set their horizontal and vertical alignment, just by setting the text-align and vertical-align properties respectively. By default, using inline-block for columns causes a natural whitespace to appear between each column, which can vary in width from font to font and browser to browser. This has caused many people many problems, and there are plenty of go-to hacky and impractical work arounds, none of which are really suitble for a production environment. Kayzen-GS allows for the use of completely usable and functional columns which use inline-block and have no white-space. Kayzen-GS works in all browsers, including Internet Explorer 6 (not that anyone uses it anymore...).