Sener,
I think it boils down to the style of street photography (SP) you do. SP is such a wide genre that comes with many approaches. It seems like you prefer shooting with larger apetures near or wide open. In these cases AF is definitely crucial and of course some of the M4/3 dominate the field in the AF speed/accuracy/reliability in the mirrorless world.
On the otherhand there are many SPers that often shoot at smaller apetures (often f/8 give or take) and shoot zone, use hyperfocal distance or combination of all the above. In these cases AF is not as crucial since the DOF is quite large. They prefer to have most or all of the scene in focus throughout to have the subject/environment(aka street)/etc be an important part of the image. For many of these shooters the Fuji AF is more than 'good enough' on top of the many reasons why people enjoy Fuji cameras.
I'm personally love to shoot at the smallest aperture possible that my ISO/SS can handle for the scene. The exception would be some types of street portraits.