Sorry man, if you could drift in GT5, but can't in GT6, the problem is you, not the game.
Yes, drifting in GT6 did take some getting used to, and required a slightly different approach to tuning...but that said, once you get a feel for it, the drifting in 6 is much much better than in 5. For lack of a better way to put it, it just feels more "real". And that goes for wheel and DS3.
Pretty much all the regulars from the drift forums have adapted, and are killing it now.
Sounds to me like you just need to put more practice in. Drifting in Gran Turismo shouldn't be easy...this isn't NFS. Ask anyone who is considered "good", and they'll tell you it took anywhere from several months, to over a year (depending on play time mostly) to become proficient at drifting. The GTP drift community is populated by some of the best virtual drifters in the world, and even they will tell you, they are always learning and improving.
What is killing the GT drift community is everything but the actual drifting itself:
-poorly modelled clutch for the wheel
-customizable transmissions that don't work with the H-pattern shifter
-no clutch button for controller
-no drift related tuning options (knuckle kits for more steering lock, caster adjustment, tire pressure and tire dimension adjustments, etc etc)
-no "free roam" mode on all tracks (ie no barriers, wrong way indicator, etc)
-no way to place cones, tough-blocks, or k-rails on the track in order to designate clipping points on a custom drift section (you know, like that thing PD sponsors...what's it called...oh ya, the Japanese D1 Grand Prix!!).
-limited engine tuning
-no motor swaps
-no drivetrain conversions
-minimal visual customization
-lastly, no livery editor.
These are the things which are causing people to flee the GT drift scene like the plague. So many from GTP have already moved on to LFS, rF, or AC...and many more are patiently waiting for the fall when the next-gen racers start to roll off the shelves.