If practiced as a martial art, aikido can be effective. But as I see it, in its current form it's failing as a martial art and as a martial way.
I can't speak for most of Aikido as I have no contact with most of the people practicing it. Training is an individual journey, regardless of the activity. As such, the purpose depends entirely on the individual.
For the sake of argument, maybe the average Aikido student wouldn't be able to throw the average Judo student, and maybe that would prove Aikido is lacking, I don't know. The issue to my mind still comes back to individual responsibility. Aikido is fine where ever people are satisfied by it. Where it fails, in my opinion, is not the problem of Aikido, but of the individual practicing it.
In all things: Assume nothing, check everything, buyer beware.