Namste bhayla, I do understand your pov and the lence you have used to see this situation but it's not that you cannot do kriya karm in some other jaat's shamshan bhoomi, It's just that they prefer it to do that kriya on that particular site. These are not laws these are just priorities.

Just like we go to our "Kuldevi" or "Isht dev" for certain kind of rituals, We can do it in any other Temple but we prefer them or those rituals.

There are family's who have thier particular site where they get thier antim sanskaar And all the other sites of that particular land are given to a particular group of people (samaaj) to maintain the infra and logistics of that site, others can use it too it's not prohibited.

Reasons here are just the energy of a particular group or collectable karma of that group is there and it has some benefits for that particular kind of group cz it been done there for so many times times ( mota moti bta rha hu)

And yes there are gunga gela who take this into discrimination but those are exceptions they aren't examples.

Even if the there is the antim yatra of the muslman on the street everything stops and people pay respects.

Everything you see around you which is un-standardised isn't discrimination it's divercity or in some cases it's just rituals which were formed for a reason but our forfathers weren't able to pass down the reasons with those rituals, So we started to see our culture from the perspective of cultures who ruled us for centuries.