Your points are well taken and they are good points as well. In turn I like to point out to other people the good point some people make:
With some experience an AIMer will learn what is more or less right and what is not working. But this also means that with mutual funds for which the only trading cost is a 0,5% fee you can AIM with very low quantities. I have done this as well.
Of course, with a small portfolio you could ask if the time spend and the money earned is worth the trouble. In the same light(or darkness) you could ask if sailing is worth the trouble, or worth the money you have to spend on it.