I turn in too early (and too late) frequently in real life - getting your line right is all part of the appeal of riding a bike, as there's much more to it than just turning a wheel.
If you're naturally talented, or well practiced, you probably don't have to think about it at all. But people often talk about having to recalibrate their turn in points after fitting lightweight wheels (significantly improves agility), so the issue is probably the fact the bike won't turn until it's leaned over enough, and that takes a certain amount of time.
In the game, the lack of precision in the controls (or practice with them) makes this much worse, and it's why it's important to focus on hitting the line first, going fast second. You have to get in tune with the timings of the bike's changes in lean angle (roll rate) before you can subconsciously use it to hit your line perfectly every time. On a real bike, you control the roll rate directly with the steering (grip permitting), but the game controls the steering for you, so you're stuck with the speeds it's tuned to use.
I did notice that very tight corners are disastrous in the new game, the bike just dives in unpredictably at the last second, and it's very easy to cut the corner by accident. I find it easier to run deep past the apex, then turn, especially if there's a wall involved...
There is a lack of coherent feedback in the camera views - the onboard views don't show acceleration and braking very well, which hurts feedback in terms of what you're asking of the tyres in that respect (especially braking). The steering seems to move the camera in a weird way, and I find that large movements (e.g. those at low speeds) are disorienting - my eyes just don't "comprehend" the screen for a moment and it kind of sends me cross-eyed!
👍 
