If it walks like a duck, quacks like a duck and swims like a duck, chances are it is a duck.
When Muslims define themselves as Muslims only (without any labels, thank you) and base their religion on Qur'an only then we could begin to assume that they are free from sectarianism.
When a Muslim claims his imam, his fiqh, his way, his interpretation, is THE WAY, then knowingly or unknowingly he is a sectarian. If the Shias say that Ali's status and succession of his and his descendants is legitimate and Shia Imams are ma'soom (free from error) then they believe their's is the right way and all those who are against them are misguided, that is very much a sect.
Followers of different sects declare their opponents as deviants and misguided (if not Kafirs). There is a readily available evidence of sects being alive and thriving on Youtube.
Some are so rigid, that they will not pray behind a different sect's imam and will not marry outside their sect.
Therefore, we have a lot of work to do before we claim that there are no sects in Islam, only schools of thought.
Watering the problem and diluting it will not work. It has to be rooted out. Why? Because the Qur'an is dead against it. It evens gives a clue: When each sect thinks it is on the right way and other is not.
It can start with schools. Children should be taught a sect-free Islam at first and later on when they grow older, they can be shown what differences exist on interpretation of Islam. They must then be told to be tolerant and aware and remain neutral and when they become adults they can make up their own minds.
For more info with respect a proposed education system for the next generation, please watch
and (part one)