That’s not how it works.
Readers can take note of the proverb/poem, “For want of a Nail.”
Not making IMPLICIT NONE the default is a crucial little detail that makes Fortran “nor here, nor there” when it comes to being serious about type handling. This has indeed led to many a bad first impression of Fortran and which, as the saying goes, has lasted with peers and colleagues I know. Moreover, mistakes have occurred, particularly with interface bodies (see the original post with what can happen with a long chain of interface blocks), that have led to teams I know not bothering with writing Fortran interfaces to production libraries that are based on processors other than Fortran. This has catalyzed the move away from Fortran.
A lot has been lost when it comes to Fortran being seen in the past tense as the lingua franca of scientific computing.
Like in that poem I quote above, the root causes all come down to little details that didn’t get the attention and importance they deserved along the way: IMPLICIT NONE not being the default is among them.
Year 2041, as the Golden Jubilee of Fortran 90, looks like a good target date to finally introduce such a change, it will be a great way to celebrate that milestone revision.