If Noah(and his family) were preachers of righteousness, then they were g'damn lousy preachers, IMHO! How could they possibly preach that many years and not convert even one soul?
As Blondie metnioned,
"Likely", or "We can assume", or "From this we can imply"
that jehober did not bless his ministry! How heartwarming and fulfilling it must have been for Noah and his family to have witnessed such a thrilling vindication of jehober's name as millions got to drown to death.
just saying!