In my opinion the word 'disable' is quite derogatory to be used for a person. They are able in different manners,not disable.

Atheist ji, and your question regarding SRM has a much broader horizon to cover from the Sikhi aspect. India has a stigma against any fraility that we as humans may possess and by golly we as humans have lots of them but we cover them up quite cunningly rather than showing them bravely and seek magical miracles for our mental and physical cures instead of accepting them so they can be improved upon. India is supposed to be the 'most religious place' in the world. My Dad used to say that the more we do Ram Naam, the less godly we inclined to become because we are looking for a quick magical fix.

Coming back to Khandei di Pahul and able bodies is much farther in the case of our awareness and improvements of things for people are able in a different ways as far as priorities are concerned.

I do not think, but please someone correct me if I am wrong that there is no ramp for the wheel chair people to enter into Harmander Sahib or any other Gurdwara which is a shameful thing. In my opinion all Gurdwaras should have chairs and ramps inside where Sri Guru Granth Sahib Ji parkash takes place so old people and wheel chair bound ones can enjoy the same Amrit Keertan as everyone else.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/general-discussion/29578-disabled-people-and-reht-maryada.html

As Sikhi is based on equality, we should allow women to do Seva inside Harmander Sahib, become Granthis and sevadaarnis inside the sanctom sactorium, and be able to do keertan inside Harmander Sahib.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=29578

So, before we try to challenge what can be corrected in the ceremony of Khandei di Pahul, let's work together to create equality in other fields first, then your query will be the natural result of the progression of the self.

Atheist ji, do not be outside this Jungian circle and watch it from distance. Become part of this circle and join hands to improve things for others. Isn't that the goal of any human no matter what faith,hue, creed one may belong to?

And shall I add that atheism is part of the same creed, that is to participate actively in improving humanity no matter what.

Regards

Tejwant Singh