It is deleted because a moderator decided to delete it for reasons stated in this chat message.
Posts in the Q&A threads are not an appropriate place to host personal remarks about oneself. Space Exploration SE is attracting traffic measured in thousands (around 6 000 daily visits). Some of the Q&A threads have been visited more than 200 000 times. Most of the visitors are directed there by search engines and are completely unfamiliar with general SE's culture, much less with that of Space Exploration SE. How many of those visitors do you expect to be interested in reading highly personal and contextual inside-jokes, and how many of them do you expect to be even remotely amused by those?
Most people who are passively reading our site's content are coming here to read mind-opening and enlightening explanations in the answers, and genuine displays of curious brilliance in the questions. They possibly do appreciate the time and effort, but certainly do not care about personal details of people hidden away behind nicknames and avatars, because why should they do? We are complete strangers to them. The inclusion of personal remarks and jokes serves no other purpose than to unnecessarily distract those readers from what they wanted to read. Not only that, as even the registered users don't have to be familiar with all the references required to understand the highly contextual attempts of humour, and are likewisely led into the state of distraction and confusion upon unwillingly encountering such unexpected insertions.
Let's consider the case of Wikipedia. If the editors of Wikipedia articles started to randomly include highly personal and completely off-topic remarks into the articles, linking to, say, social media posts where somebody said something personal about the particular editor, would you be happy about that? Let's use the specific example of the Wikipedia article about acetic acid:
Acetic acid has 349 kcal (1,460 kJ) per 100 g. Vinegar is typically no less than 4% acetic acid by mass.
Because of my preference for sour foods [link to a Facebook post] I am considered to be the resident vinegar purist and never use vinegar containing less than 10% acetic acid.
Legal limits on acetic acid content vary by jurisdiction. Vinegar is used directly as a condiment, and in the pickling of vegetables and other foods. Table vinegar tends to be more diluted (4% to 8% acetic acid), while commercial food pickling employs solutions that are more concentrated. My grandma never liked pickling cucumbers, funnily enough. The proportion of acetic acid used worldwide as vinegar is not as large as commercial uses, but is by far the oldest and best-known application.
I highly doubt anybody would be happy if Wikipedia articles were to read like that. SE's philosophy is significantly similar to that of Wikipedia, so why should it be any different here?
From Help Center:
Do not use signature, taglines, greetings, thanks, or other chitchat.
[...] Your user page belongs to you, so fill it with information about your interests, links to stuff you’ve worked on, or whatever else you like!
If you use signatures, taglines, greetings, thanks, or other chitchat, they will be removed to reduce noise in the questions and answers.
Avoid overt self-promotion. The community tends to vote down overt self-promotion and flag it as spam.
which arguably also includes self-promotion disguised as self-deprecative humour.
I have reported, so far, two instances of you including irrelevant and self-focused remarks in your posts which were linking to that chat message. More are to come.
Note the fact that I have reported those to moderator attention only after you had rejected two of my edit suggestions attempting to remove those unnecessary and off-topic remarks (the first and the second).
On the subject of your desire to wear that as "a badge of honor", there was nothing stopping you from copying the contents of that particular chat message and including it in your profile's bio in a blockquote. Q&A posts, however, are not an appropriate place to be including such things.