SSA everyone.
I have a simple question. Do you consider someone who follows Sikhism to be less Sikh if they don't keep their hair uncut?
My short answer is YES.
Please, before you get angry or defensive, hear me out.
The SRM definition of a Sikh notwithstanding, being a Sikh involves more than a set of beliefs, imo. "Following Sikhism" involves keeping kes.
Being a Sikh is an experience, a set of experiences, in fact. Part of those experiences involve being willing to be readily identifiable, to have the courage to stand out, to be different.
One way of doing this prescribed by our Guru jis especially by Guru Gobind Singh ji is to keep kes. I admit that this is difficult - in different ways - both for men and women. A man with waist-length hair tied up in a turban doesn't look much like the boy next door, unless you happen to live in Amritsar or Anandpur Sahib. (Even there, it is getting less common.) Having hairy legs and underarms, not to mention unruly eyebrows, is likely to get a girl made fun of by her peers, even worse should she have the slightest hint of a mustache. Whoever said it was easy.
My experience is that most worthwhile things are not easy. Hey, I didn't create this world, I just live in it.
My husband and son died rather than cut their kes. Of course, cutting the kes wouldn't have been a simple haircut, it would have been a denial of their identity, of everything they had held sacred. It would have been an act of cowardice.
Please read on before blowing up at me.
That said, not every Sikh feels the need to keep kes. It is a personal decision. If a Sikh does not find it meaningful, if s/he isn't ready to stand out in a group, that's where s/he is at this moment. If it isn't meaningful, perhaps s/he needs to cut. I think that's sad, but possibly necessary to that individual.
Personally, I feel that looking like a Sikh is part of being a Sikh, and not the only part. Other things are important, too. I am not among those who says that if you don't keep kes, you aren't a Sikh, but again I say, you're missing something if you don't.