I realize colorless Pokemon aren't quiet as...shall we say critical as those Pokemon that are of more specific types. On the other hand I have always viewed colorless Pokemon as cards that can go into any deck because of their versatility, they don't care what kind of energy they get. True they don't get any weakness advantage but most Pokemon are not resistant to them either. It's just straight up damage, which is basically what happens in a lot of instances. Yes electric will be strong against about half of them (with fighting being strong against most of the other half) but water types have to worry about the same thing too, and we won't even get into the fact that pretty much all fire types worry about water.
Think about this though, in this regard dragons are no better than colorless, in fact can be considered worse. RIght now they are strong against their own type only, and are weak (for now) to themselves and to fairies. Energy wise they are worse because they want at least two different types of energy (fire/water for Salamence, fighting/steel for Haxorus, for example) and have no energy of their own yet. Of course there is double dragon energy but with it not being revealed yet we have no way of knowing how helpful this really is. Meanwhile the colorless Pokemon don't worry about what they're running with. Psychic, water, grass...it's all the same to them.
I don't know necessarily if this should be overdone, but some colorless Pokemon could easily get a similar ability that Lucario had, as well as the alternate (and POP) Rotoms. Something like a Colorless Xatu with an ability that reads "Once per turn, before you attack, you may use this power. Xatu's type is psychic until the end of your turn." That way for attacking purposes any benefits still apply but afterwards it's colorless. I mean even a psychic Xatu or a water Pelipper shares the same weaknesses as if it were flying, so why not? I think this would be great on a colorless Butterfree, and then grass type Caterpie/Metapod with colorless attacks.
I know those from a competitive perspective may view colorless as a waste of time and of course the company has to consider that, but the company also has to consider the collector aspect, and the fact is there are people who are more likely to collect an all new type of Xatu, Shaymin, or whatever than to get yet a new version of the same type. Then of course there are people who collect regardless, but that's not relevant here. The point is that they have to consider the collector as well as the player, regardless of whether they be casual or competitive.