Glyphs also take up one-third the space of ink. If the ink stockpiling reaches an unmanageable level, the risk of losing glyphs may be worth taking if it frees up two-thirds of your bank space for more ink or glyphs.
(For those worried about numbers, I stockpiled 37,000 glyphs with 12,000 ink left over for Glyphmas. My ink stockpile for MoP is already well past those numbers. You can never have too much ink.)