Aikido is absolutely effective at what it was developed to do, and that is to neutralize sources of conflict ranging from personal conflicts you may have between things like your balance and gravity, to verbal altercations, all the way up to and including multiple attackers armed with various hitting, cutting, and stabbing weapons
I think their argument is that there are better, cheaper, and safer ways to do these things.
For example: balance and gravity. Buy a 50 dollar bosu ball and do some stability exercises in your living room. Cheaper and will get you better results. Also consider doing some yoga at the Y or buy a decent DVD.
Verbal altercations. Not sure how aikido really helps us here since we do not typically practice verbal skills in aikido. I think we do a decent job of imagining what we might do in a given situation, but in reality when faced with someone who is not really all that interested in reasoning with us, well not sure we can really do much to dissuade him. Again, that was there point at the beginning and I must say i agree with it.
multiple attackers. Again, I agree with there logic for the most part. We don't see overwhelming evidence (or any) that aikido or any empty handed martial art really does much to improve our lot in life in this arena.
now I do find there are some flaws in there logic, and of course, they picked three very good examples that back up there argument.
Overall though, for the framing that they did...yeah I agree with there assessment. For self defense, there are much better uses of your time than spending it in a dojo doing what most folks do.
ome will look up to me with some elevated level of respect or awe which is totally undeserved, and I'll feel a bit guilty about that until I set them straight and a bit insignificant after I do. Some will look at me with caution as if we were a threat or a challenge, and I'll feel a bit anxious about that until I set them straight, and again a bit insignificant after I do
awe...something I have never experienced. Most folks look at me like I am crazy for doing what I do. I don't worry about it too much cause I like what I do. also, humor goes along way in life too I have found.