My two cents on teachers/gurus:
In the real world, there is no such thing as 0% or 100% or infinity. Everything is in between. The guru is important - yes. But to say that the guru is God and decides the student's fate... is a little on the extreme side. What is the logical conclusion of this? Children who pass through 18-odd years of obeying all orders from one human being will only grow to yet again obey all orders of another. In a system of unquestioning adulation and respect, there is no opportunity for the follower to cross-check on the abilities of his/her leader.
I know nothing about the Gurukul system, but I have been a teacher myself for an year and in an organisation where the importance of the Guru was constantly drilled into our heads, and where my students were the typical helpless slum children that have no one but me to look up to. I've seen that it's all too tempting to assume the powers of a God, to believe that I alone hold the keys to 34 destinies. I've been through that and came out despising myself for the monster I had become in the process. There are some roles and structures that had best be left to the Gods.
After that experience, I have interacted and lived for a considerable time with unschooling children and their parents. What I found was that rather than the absence the all-so-critical guru, these kids had innumerable gurus all around them, and had developed an ability to pick and choose the ones most suited for the circumstances - to follow what was meaningful and discard what wasn't. They learned flash programming from me for an hour and then went on to create some amazing films, without even once having to elevate me or lower themselves. We exchanged skills like equals. And then again, in many aspects they became my Gurus and I learned immeasurably from them.
I would say that we should live in a multiplayer world, filled with multiple paths, players, options and directions.
And just like how the importance of a guru in a child's life is so often touted as critical, it is said with equal gusto by often the same parties that competition is essential to create a good and successful human being. Today there is mounting evidence that this isn't true either. What else in our age-old wisdoms may be debatable?
Further reading: Children Educate Themselves IV: Lessons from Sudbury Valley