I strongly suspect that the whole reason this is even talked about is because 25 lucy's on SST causes technical problems, particularly when in human base.
Is Lucy spam ever a legitimate strategy? Yes, for cover fire and to buy your builder time to rebuild defenses. On the alien side I use eggspam. While humans try to deal with eggs all over, I rebuild base using the BP's the humans recover for me as they egghunt (I did this last night while humans bragged about killing all my eggs, we won)

On the human side, people spam the entryways. Chainguns and pulse are effective, but lucy is most effective cause anything smaller than an adv_Dragoon usually won't even attempt it (ok, dretches will try to slip by.) Anything that does survive can be dispatched quickly.
Is Lucy Spam a good strategy? Not usually, you block movement through a door, leaving aliens to sit and gain evols. Not smart. Humans going through the door will most likely get pushed into the aliens to be dispatched quickly. It can be very helpful for short periods of time.
On the rare occasions I see lucy spam, it usually doesn't last very long, and aliens deal with it. This is behavior that certainly shouldn't be cause to be kicked. I don't even want to think about SST on this one, see their forums to find the many "definitions" of lucy spam in use there.
/My 2cents