While I agree I do not agree entirely.
Sometimes people do that because they really like your meme and really want you to know it, but have nothing interesting to say on the meme itself. Other times people are in the begging for up votes stream, and honestly that is totally acceptable in that stream. Some people use it as a form of acknowledgement when they don't want to leave a thread hanging. We sometimes may do that when users seem discouraged because they are not getting comments on their memes but again, we have no interesting comment idea. So they may get such a comment.
I do not care for generic comments be it in template form or a simple text comment saying, Up vote" when someone does this and only this. There are a few users who do this because they want points and can churn this comment out in high volume, and they know that someone will up vote that generic response. You will usually find that the ones who do this have reposted the same meaningless response on 200+ memes all over the site, as well as using it as a reply in comments. I think if this generic commenting and replying is all someone ever does then yes, it is lazy and lacking. But most of us do better than this most of the time.
However, While I do not care for this practice and refrain from this sort of activity most of the time, excepting when it is called for, I dislike policing others even more and only offer my input when it is asked of me. Perhaps if someone comments on your meme in this way and you do not prefer it you would be better off letting that individual know so that they may be more creative in the future or refrain from commenting on your memes to start with.