to success in pre 2.1 titan HM there are simply 3 criteria

1. almost flawlessly avoid titan's aoe (either by living close to the datacenter, or having under 0.5s reflexes at all time, or memorization of titan's attack patterns)
2. managing the heals (healer keep the tank and members alive, tank gets prepared for MB)
3. have enough dps to brust down titan's heart (by people who 'can't dps' but with good gear, or people who 'can dps' with minimal gear. DF=4 DPS)

a DF party can very hardly meet all 3 criteria therefore easy to fail.
those who succeeded also are more likely to have been carried by partially pre-made group

Titan HM is perfectly doable with ilvl60s, and the ilvl doesn't really have too much to do with a group's success or failure here.

I have seen way too many people, tank, heal or dps alike who spent a lot of time to collect their gears and think they are automatically the best, but in fact those gears become a complete waste on them.