Several nodes like 10770256469 were converted from uncontrolled to marked. As to why uncontrolled is preferable to marked it is simple, it seems to be the community consensus, I say this because the Id tagging schema has “marked crossing” tagged with crossing=uncontrolled. 

I also personally prefer if it because wether or not a crossing is marked or unmarked is denoted by crossing:markings so uncontrolled is preferable because it lowers duplication in tagging meaning and keeps wether or not a crossing is signalized to uncontrolled vs traffic_signals since that is the difference between the two.

Happy mapping,
Udar