So I was watching a FFA game which highlighted this, and its time imo it got a handle on it.
Grumpy being attacked by two skilled players (one TS 48 to give an indication), with varyed t2 armyies both coming at Grumpy from two seperate directions
Grumpy, has 3 kbot labs and 34 nanos, spamming them
that was enough to completely stall the attacks for both
and actually cause resteat, while he then moved to unit creation.
He had very little unit army and certainly nothing to match what was coming at hi,
The cost of those 3 labs is 'tiny' in comparison
Thats zero skill in my book
Fleas are a highly skilled unit in early game, and warrent their inclusion, but aimlessly spamming them on mass hurts true gameplay.
Ive also suggested when you hit certain tech levels (e.g. t2) or eco levels (at a level) they start to get restricted to stop this type of play.
Ive just used this game as an example but its so common now.