So this collage of Albert's line in the original series + the Bob blob in Part 8 has popped up in my twitter feed, and I think it brings a lot of it together.
My feeling is that the whole lore with the a-bomb doesn't literally mean the a-bomb brought all of the evil into the world, but that the bomb is the utmost representation and a powerload of the evil that already resides in men. The thing is, its power is so great it had the capacity of exposing this in a very raw form, unleashing it into the world and arguably creating some kind of disturbance between our reality and parallel dimensions (i.e. Black Lodge, White Lodge, room-above-the-convenience-store, room-in-laura's-painting). The mother is, then, man-made, a byproduct of the concentration of this pure evil force - which, as we now should know, creates the garmonbozia Black Lodge beings adore so much.
On another realm (which I reckon might be the White Lodge or somewhere in between), The Giant and Señorita Dido seem to work together to bring light into our world and counteract the darkness. That golden is the only significantly bright colour in a nearly all B&W episode called "Got a light?" makes it inevitable to address Laura as a "good" force. As someone pointed out, and I noticed it while watching too, the golden mass of light which later becomes Laura's blob is shaped like an uterus. So, while Bob's dark blob seems to come off Mother's head (and mythologically, the head, matters of the mind and such are often connected to a masculine energy), Laura's light blob comes from a womb (which sprouted out of a mythical being's head, but that's on another level).
Does it contribute to an unfortunate trope? It does, if you look at it simply like Good x Evil, but we are in Lynchian/Frostian domain here. Nothing is as it seems. Lynch's intense involvement in transcendental meditation is very likely going to influence this imagery and narrative into a reflection rather than an outright morally correct conclusion. Very often, in the world, evil trumps good - Laura, for instance, was so corrupted from an early age, she didn't even stand a chance against Bob.
I think the whole Good x Evil debate is much more centered in the balance of good and evil within each person - which is why, very fortunately, we have lots of complex characters supporting this debate, Cooper being one of them (people tend to think of him as 100% good, but he does have an evil doppelganger which wouldn't exist if there was no complexity to his character).
EDIT: My guess about the Cicada Frog, Moth Frog or whatever you call it: Laura's blob became the egg as it came down. The frog is "good", climbing into the girl. As for the Woodsmen, they seem mighty evil, but they might also be a byproduct of the imbalance caused by the bomb.