As Oded's answer points out,
Anything that is not relevant to the question/post is noise and should be removed.
Irrelevant text can harm a question's readability and detract from the long term purpose of the site.
Removing "Hi", "Thanks", "Appreciating any help", etc. makes questions
more valuable for their future readers by making them look less like
problems that only happen to their askers. (source)
The Over-Meta has a lot to say on this topic. A few highlights...
Meta SO has similar community standards in place to protect the quality of the site and maximize utility for future visitors. Some highlights...
Guidelines when removing fluff: (1, 2, 3)
- Do not remove context.
- Fix everything. Don't leave other errors in place.
- Do not suggest an edit that requires a review for fluff alone. These should be rejected as superfluous as suggesting minor edits imparts extra work for reviewers. Users with editing privileges should strive to complete minor edits with more substantive or holistic edits, but minor edits from these users alone are not abusive.
- Avoid minor edits en masse. Users with editing privileges should be mindful that repeated minor edits bumps questions to the top of the activity list. Avoid this unless the post is already at or near the top of the activity list.
As pointed out by @MichaelT's comment (source),
The politeness expressed by "hope this helps", "thank you" and "hello"
is all similarly problematic in technical writing. Stack Overflow, as
a Q&A site, strives to be a technical resource akin to encyclopedias.
That writing style that makes it useful as a technical resource
precludes pleasantries and formalities. Even in cultures with
formalized pleasantries and courtesies, one doesn't see such
pleasantries in the technical writing. The reason for removing "thank
you" is exactly the same as the reason that "hope this helps" isn't at
the bottom of every Wikipedia page.
Assume every OP is thankful and appreciates the help.
If you want to express gratitude, then upvote the helpful content and accept an answer for your question when it resolves your question. Answers that receive upvotes move up and get more attention.
Response to Mark L. Stone:
I acknowledge Mark L. Stone's comment about the flurry of edits and take responsibility for that (see also his original question). Indeed, my edits were completed on Oct 22 at 2:11, 2:24, and 2:25 for three of those revisions. The other was Oct 15 (~1 week earlier). I will work to do better on that point and avoid bumping many questions at once.
To be clear, I view my edits individually as acceptable since I generated no work for reviewers. However, three (3) of them collectively were done very close together, which bumped them to the top of the activity list; this was unacceptable.
Image refers to high frequency of minor edits only