Also, Dennis Ritchie developed Unix while simultaneously developing C, so it's not hard to imagine that he added features to the language to simplify his Unix code. At one point he added 100,000 lines to Unix within a year, so he had reasons to make the language ergonomic.
"To encourage people to pay more attention to the official language rules, to detect legal but suspicious constructions, and to help find interface mismatches undetectable with simple mechanisms for separate compilation, Steve Johnson adapted his pcc compiler to produce lint [Johnson 79b], which scanned a set of files and remarked on dubious constructions."
So although C designers saw the dangers of C and provided static analysis from the early days, many C developers keep ignoring them.
I, for one, see C as both unsafe and unergonomic. The many features of C++ can be seen as various attempts to make some or another thing expressible in C -- parameterized datatypes, namespacing, encapsulated resource management -- that wasn't before.