In society, it seems people desperately want to be part of a group or community, even if they say that they do not. Nobody truly wants to be an individual -- or at least not many people.
The people who say that they are to be an individual typically fall into two camps:
2) People who create a community or identity based around 'individuality', by calling themselves 'MGTOW' or 'Nietzscheans' or whatever. So, um, also liars.
Wanting to be part of a group, by the way, doesn't mean that one doesn't harbor a desire to stand out, or be special. Humans are competitive creatures by nature, so many people do harbor a desire to stand out and feel powerful (others don't, and are happy with their rank and file), but, to be competitive, you need to be competitive within a framework. You need a goal, and, whilst you work towards this goal, you also require a 'good' and 'bad' to define whether things work towards this goal.
For example, in football, a 'bad' kick would be one that doesn't facilitate the goal of, well, scoring a goal!
Being competitive and being an individual are not the same things -- the best, most competitive office worker, who complied with all his bosses orders super quickly, is not very individualistic.
Competition is just wanting to be seen as the 'best' in your group.
Selfish desires (which are linked to competition), often stem from a need for validation from various members of your group -- and so also aren't incompatible.
Okay. So: why do humans feel a need to be a part of a group? I've narrowed it down to two seemingly opposed reasons:
1) The desire to stand out -- this is why we don't have one monolith community, but instead many different communities: different subreddits, hobbies, political groups (to the extent you define yourself by your political views), etc. To be part of a community, you must have an identity, and to have an identity, you must be contrasted with other people or communities. Being contrasted could also lead to you feeling superior to those who are different from you. This is also what creates competitiveness, and thus, hierarchies.
2) The desire to have someone backing you up -- by this, I mean the desire to have people you can relate to; people you can feel safe with -- basically, what you think of when you think community.
This is why the stigmatization of groups sometimes doesn't stop them from chuggin' along: this stigmatization reinforces their identity (which is firmly contrasted with most other people's identities), thus creating a feeling of superiority, and they, if they don't disassemble, they must feel like they have people to relate to.
Some people are stronger in one instinct than the other: for example, MGTOWs are probably higher in first instinct, and so their sense of pride overrides the feeling of sadness from not being able to relate to a lot of people; others, who are in communities which many people are in, such as mainstream religion, likely feel that community is more important than an abstract feeling of specialness.
However, note that if the first instinct I described 'went crazy', it doesn't mean individuals would be created. Instead, many small, segregated groups would be made, which are highly competitive in nature. Each community would have qualities that they value as their goal and build hierarchies over that. A community is still essential, however, to build these goals in the first place. An individual cannot compete with himself!
None of these instincts are good are bad in themselves, by the way, and I am not advocating rugged individuality, since society would collapse were it not for 'stupid' people. Nor am I advocating for blind groupings, since many revolutions were caused by individuals. Both of these instincts, be they balanced, or in an extreme, could be 'good' or 'bad' -- none are something in and of themselves.