As demonstrated by the argument that blink deserves elimination because of the past, the big rationale is punishment - premised upon anthropomorphizing an HTML tag.
What I remember about the days of blink is fucking amazing the web was. The driving ideal was connecting everything to everything else - not creating gated communities of cul-de-sacs. What was far more annoying than blink was auto-playing music.
Now in fairness, if the web has ceased to be a source of annoyance since, I must not have noticed. Was there a memo?
if you read the comments thread on jwz's site there's a discussion that concludes that blink doesn't blink fast enough to cause seizures- There's specific MIL specs they cite.
It's just change.
Blink never hurt anyone.