so after all these years, BB still inserts dim7 chords when I -only- write dim, presuming them to be the same. They are NOT, anybody who studied tonal harmony properly knows that. Try this progression, a circle of fifths:

Cm, Fm, Bb, Ab, Ddim, G

all sounds well, IF the Ddim is played as a diminished triad, spelled D,F,Ab. Now play Ddim7 (D,F,Ab,Cb) and hear how ugly the Cb sounds. And yeah, in the case of a dim7 chord here, it's called Cb, not B.

Dim7 chords require proper handling, and they often introduce notes that are outside the key. In this case it sounds bad although all the notes are diatonic. But the Cb makes an augmented second with Ab, which is why it sounds really corny.

And yeah, in jazz no one would probably care. But not everybody cares about playing jazz, either. If you stick that chord in a pop song with the Cb, it will stand out like a pickle in your cornflakes. That is, badly.
The right place for a dim7 chords in the key of Cmin is Bdim7. Nowhere else, unless you are modulating.

Triads are triads, seventh chords are seventh chords. They are not always interchangeable.