Well Smalltalk was designed to be easily mastered by one individual so its browser can look the entire hierarchy in two clicks and list the senders or implement

Well Smalltalk was designed to be easily mastered by one individual so its browser can look the entire hierarchy in two clicks and list the senders or implementors of any method you want in one keystroke. Not to mention that its debugger can restart the stack at any point, change code, recompile it on hot and continue in the same thread. So, I guess yeah, if you don't have great tools anything is "so hard to debug"