That's a pretty one-sided post-modern Western view of missionary activity...
I met a lot of 'natives' during my time in PNG who found happiness in being freed from the bonds of fear, violence and ignorance associated with the dark practices of some of their traditional ways. Missionaries have also done a lot of work to improve the health and wellbeing of many people, providing healthcare, education and facilities that simply wouldn't have reached them through other commercial avenues - especially to the marginalized and underprivileged. It's easy to point fingers at the mistakes, but it is a bit rough to condemn those people who have generally self-sacrificially given their lives in service for the benefit of others.