While I agree with you that follow for follow is not an effective long-term strategy, I'd argue that it also not an effective short-term strategy. Earlier today I stumbled onto a user who's been here since May. I don't remember the exact numbers, but he/she followed something like 1,500 accounts and had a similar number of followers. But only had built up only about 30 SP.
The effort that must have gone into so many spam comments could instead have gone into maybe a dozen quality posts and some cogent comments that likely would have garnered more SP than that.