Why do we have to label our children in order for them to get them the help they need.
Because you are dealing with bureaucratic systems that need labels.
That's pretty much it.
You have three options when your differences leave you so far from normative experience that you cannot
participate in certain life (or educational) activities the way that others without those difference can and do-- often without even thinking about the task much
Change your environment or the tasks required of you-- limit yourself
to mitigate the difference, in other words.
Accept that you will not be able to do the things that those around you are doing-- accept poor performance and access as your lot in life, and work as hard as you can to make up the difference on your own, without asking anyone for anything
Seek ways to compensate or mitigate particular barriers within the normative environment so as to allow your access to be more similar to those who are normative-- usually this will involve some kind of formal or informal arrangement so that the method
of the life activities in question may be modified somehow.
Yes, everyone has quirks, limitations, and differences.
Not everyone sees a clear need to use choice 3 for every one of them-- but sometimes that is a difference in how large the difference is, how important an activity is to an individual, etc.
This gets to the heart of what constitutes "substantially limited" when determining whether or not a person is afforded protections under ADA, actually. Advocacy requires a label, because it's about rights, not largesse. Largesse is fickle when you're dealing with people. Rights are far less so.