Non-converting toys in the mainstream action figure line tend to be marketed at infants, who would have no attachment to these characters. These characters would appeal to G1 fans, and as such the Generations line is probably the most appropriate line to release them in, but then how many non-convertible CHUGUR figures have they ever released? The only thing that came close in the mainstream action figure line was Alpha Quintesson from Transformers Energon, but that toy was never released here and I don't know how well or poorly it sold overseas (it's not a great toy ).

I think that the Alligatorcon is definitely doable as a Generations figure. They could even retool TR Skullsmasher. The other Quints on the other hand would be tough, because if you gave them alt modes then it would make their Quintesson modes look less G1 accurate - cos they never transformed. But if they don't transform, then they're not going to appeal to kids - and as much as adult collectors love Generations, the line has to also appeal to children (a lot of kids at my daughter's school like to play with Generations figures - I occasionally stumble across them in the playground).

I think that the next best option for Hasbro to release G1-accurate Quintessons is release them as build figures, like what they did with Transmutate. You release a wave of toys and each figure comes with a part of say the Quintesson Judge. Collect them all to complete the Quint! But yeah, from a business POV I don't think it's worth it for Hasbro to release Quintessons as stand-alone action figures in the mainstream line.