This heavy status while on mount...

[Vespar]

It's a mechanic lazily copied from WoW, designed to give the player a sense of danger when traveling past high level mobs. I've never once died to it, so chalk another one up to "we copied WoW because of sub numbers".

I dont necessarily think it was just copy pasted from WoW, especially because of sub numbers, but your other point is valid. It is there to give us a sense of danger. The problem is that we're strong enough to own the mob causing heavy within a few seconds, so its just become more of an annoyance then a danger.
Now if there is a low level person riding through a high level zone, it may be cause for worry. but that doesn't happen often... I think it would make more sense that getting hit for a certain amount of dmg would knock you off your choco forcing you to fight the monster, instead of just continuing to run until they de-aggro.

Personally, I miss the days of XI, when we could just jump on chocoback and take a leisurely stroll and see some sights.

[MistyMew]

Personally, I miss the days of XI, when we could just jump on chocoback and take a leisurely stroll and see some sights.

EXACTLY, lets have that here as well SE