Is that really a bad thing? If we went down that route we could still make our best efforts to careful mould it into a useful and well balanced threat with the right movepool, stats and ability to compliment that type's strengths. The key word is carefully because it would be important to give it a useful niche but not to make it obscenely powerful or hard to wall. If it is carefully considered we could just as well end up with a unique and interesting threat of a type that we don't normally see in OU, and isn't that what the goal of the concept is - to see the effect a traditionally 'bad' (and hence lesser seen) type has on the meta-game when it has been well considered and built and given just the right tools (which arguably Game Freak has failed with some types so far). That in itself would be interesting and a success imo.
Very few mono-types are inherently bad as a result of typing alone. Reposting from #cap:
Code:
<bugmaniacbob> most monotypes don't really have a conceivable disadvantage
<bugmaniacbob> other than being limited offensively
<bugmaniacbob> whereas with two types we can propagate the weakness of the typing
<bugmaniacbob> the way I see it, if you put typings on a spectrum
<bugmaniacbob> the best dual-types are up at one end, and the worst are up at the other end
<bugmaniacbob> and most mono-types are sort of in the middle somewhere
<bugmaniacbob> thing is that limited coverage is easy to solve
<bugmaniacbob> just add... well, more coverage, or bulk up or something
<bugmaniacbob> a proper typing disadvantage is much much harder
<capefeather> like a 4x disadvantage?
<capefeather> or many disadvantages?
<bugmaniacbob> either or
<bugmaniacbob> you have your water/dragon, and you have your rock/ice
We could quite easily construct a well-balanced threat given a mono-type, but that's just it - it would be pretty easy. I'd rather that this CAP gave us a bit more of a challenge, and most dual-types have so much potential and so much wrong with them that I feel it is so much more worthwhile to try to make their typings something positive, rather than mono-types, because the thing with mono-types is, we already know what their advantages are, it's not going to tell us anything we don't know, and, well, we already know how it will work in practice, more or less. It'll be another strong, fast Pokemon with some way of working in practice, and something that makes it usable.
@Deck Knight:
I should probably post here for clarification. As far as I can see, the three options that are presented to us are as follows:
1. Mono-type that hits things and has some sort of strong defensive typing but weak offensive typing
2. Dual-type that hits things and has some sort of strong defensive typing but weak offensive typing
3. Dual-type that hits things and has some sort of strong offensive typing but weak defensive typing
I'm having trouble seeing how any of these actually helps to fulfil the concept. Just about every single mono-type is on average better defensively than it is offensively (unless it's something like, say... Ice), and I don't see why we have to make our typing advantageous outside of the area it is supposed to be operating in - why, indeed, we have to make something like Poison or Steel a powerful offensive threat, or give a defensive Ice-type a second typing to nullify its weakness, as opposed to concentrating on its plus points, like being able to wall dragons or whatever it might be.
I'm supporting whatever allows us to propagate both weaknesses and strengths, rather than cover them up, to create a Pokemon with a viable niche in the metagame that allows it to
counter specific threats and to
provide a role on a team, rather than just being another generically strong Pokemon. In essence, what Celebi is, or Claydol could have been. I am fairly certain that this is the second option, but I am honestly not sure any longer.