Well, from what I've gathered, the Zenith Relic Weapon was on par with the Raid Weapon at the time of its release (putting it right up there with the T5 Raid Weapon). So actually the Relic Weapon, when it FIRST came out, was immediately better than the Raid Weapon so you might want to retracted that statement of it NEVER being stronger than Raid Tier content on release.

It was only after the Raiders whined about it (from what I've heard) and then Yoshi-P changed it so Relic Weapons were never again better than the Raid Weapons. So when the next Raid content came out the Relic was also behind then (putting it 5 ilvl lower than the Raid Weapon) making it second best instead of BiS. It was only until the end of the Relic's life cycle in 2.X that it became the BiS Weapon to get along with the T13 Raid Weapon.

The Relic just becomes obsolete soon after when the next Patch comes out with new Weapon that have better stats than the Relic. Only until the Customize Stats for the Relic comes in, most of the Relic are subpar to the easier Lore and faster to obtain (depends on Player Skill and Teamwork) Savage Raid Weapon. We'll see what the next step in 3.3 (or was it 3.4?) has to offer for the Relic... I'm going to work on my Relic, but the NIN Relic for my main has such horrible stats on it.

It's an investment weapon, but it really puts a dampen on the spirit to work on the earlier parts of it. Well these things aren't ever that easy, but at least make it fun while working on it. It's like a chores... no one EVER wants to do chores. :P