Those two criticisms of YAML are at bottom of my list. Space as delimiter and lack of strict typing is what screws me over on daily basis as SRE.
Fair, YAML has a lot of usability warts, and those suck too. Although personally I really do hate how tough it is to tell apart arrays and objects, at least with the most common YAML array/object style.
This. I hate how all these serialization/config formats come out of dynamically typed languages. Static typing is a must. Then so many classes of errors go away.