A deliberate act would, from the descent profile, to be something that should be considered. Why is the possibility of suicide immediately discarded just because its an unpalatable scenario although very difficult to ascertain.
Be careful when you say some are discarding it. This sort of speculation has a huge impact on the family and friends of those involved, in any accident it's a possible cause, some more so than others, but it really is insensitive to others to call it out until the family has time to process it. It's similar to releasing names and such of those involved before next of kin have been notified. If it turns out that the speculation is right, great, you win the ego battle of who was correct, if it turns out such speculation is wrong, the family/friends just went through months/years of wondering what they could have done to stop it for nothing.
If the flight controls were rigged incorrectly then it would have become apparent during the previous circuits with the instructor.
Continuity only means the wires run from A to B. That does not rule out a jam or some other factor. It still does not sit with me that you would take flap to turn base for a normal landing and then suddenly push forward, why bother taking flap?