I was reading a blog post the other day that included a number of very similar comments. The blog post itself wasn't hugely important (feel free to read it here). The important part was that the blog post author was showing an implementation of something, and that implementation could have been simplified by using a different API call. Several of the comments pointed out the existence of this other API call.
This is all pretty simple, and quite common, but let's look at HOW they pointed out that the author's implementation could have been improved. Here are three comments that all say the same thing:
They take quite different tones, even though they're saying the same thing. Comment 1 is very short and neutral in tone. Comment 2 is quite aggressive, even belittling (or teasing, depending on how thick your skin is) the author. Comment 3 is much more gentle, posing feedback in the form of a question, even though the question almost certainly presumes an answer of "no advantage. I should use DictReader.". Question 3 is also the only one that provides a link to the referenced API call.
None of these comments is inherently better or worse than the other. Using the tone in comment 2 has the risk of making others think you're kind of a jerk. Using the brevity of comment 1 probably works best when it's safe to assume some level of knowledge (e.g., that the user can go find the docs for csv.DictReader). Comment 3 is the least likely to offend but the most likely to make the speaker look tentative or soft. The point is more that you can express the same information many different ways. Take into account your relationship with the recipient of the comment and the type of comment, and use that to find an appropriate tone.