All but one of the DXers I have met at either my home, club meetings, or DXpeditions have looked presentable. The one exception was a DXer who at the time was long-term unemployed in a rural area, but even he eventually improved to an unacceptable standard of appearance years later.
The average DXer is of at least a conservative mindset, hence that is reflected in their appearance and personality. The same is generally true for other other individuals seriously involved with "geek" hobbies such as chess, computers, electronics, optical astronomy, radio astronomy, paranormal investigation, stamp collecting, robiotics, aircraft spotting, photography, weather forecasting, share trading, SETI, science fiction, stock market investing, software design, physics, kit models, astro photography, puzzles, intelligence tests, and more.
Bill Gates, in my opinion, could be considered the archetype nerd, especially back in the mid to late 1970s. By default, his appearance, personality, and choice of associations was on the conservative side.
But there are those very few exceptions to the rule. In Australia for example, there were two well known DXers who actively indulged in heavy drinking, and eagerly promoted this via their web pages.
Obscene language among DXers is in my experience rare. The real test is the largest sample available such as U.S. NRC, IRCA, and WTFDA meetings.
I have little experience with regards to the ham radio community. But from what sample I have seen, most of them are more conservative formal types. But there is also the minority that are exceptions.
The average person has no comprehension or emotional precedent for any DX related activity. In other words it is completely off their proverbial radar. The same can be said for the average DXer who happens upon a university geology student analysing rock samples. What we as DXers assume other people are thinking is usually inaccurate. Hence in a practical setting when a DXer is sitting at a public park bench table listening to distant signals using a ULR + FSL, virtually all onlookers don't even notice or care. That is the reality of life.
In terms of dress standards, these days a person really needs to go to great lengths in order to stand out from the universe of dress styles. I tend to only notice extreme examples such as alcoholic hobos with long unkempt beards and hair. The average DXer by default, looks acceptable. DX club photos confirms this.
Intuitively we may assume that we need to promote the hobby in an attractive light in order to maximise the chance of attracting others. But in reality, the hobby chooses us. Most DXers seek out the hobby from an early age. This is because our genetic makeup from birth dictates what interests are taken later in life. The broadcast band DXer occurrence rate is circa one in a million. This extreme rarity largely precludes environmental factors. For example, I only know of only circa 20 broadcast band DXers in all of Australia. The circa 1 in 10^6 occurrence rarity reflects the reality of extreme provisional genetic permutation.