Monospaced fonts simply mean that the horizontal width is constant. While this also means there aren't any kerning pairs, it is a different concept. Simply disabling kerning does not mean a font is monospaced.

Kerning is a table of pairs that allows them to have more aggressive advance values. For example, with a sequential 'V' and 'A', the 'A' could be moved closer to the 'V'. But kerning doesn't have anything to do with the fact that in a variable width font that 'I' is narrower than 'X'.