At first it may seem heavy-handed for a developer to rremove blink support from Firefox, but it turns out that blink was never part of any HTML standard. If you still want to have blinking text - no doubt to accompany your animated GIFs - There is a way to do it in HTML5 with CSS animations: http://fredericiana.com/2012/11/04/html5-blink-tag/

Link: Firefox Removes support for Blink tags