i know you guys don't want to hear this but the simple truth is that the tibetians have more of a right to there own country then the sikhs have to any part of the indian subcontinent.
tibet was a very isolated country consisting of an overwhelming majority of ethinic tibetians. it remained that way for hundreds of years until the chinese only recently invaded. although others did conquar tibet before the demographics remained the same until the chinese took over and started encouraging people of chinese ethinicity to move there.
in contrast punjab is home to many different religious groups and the ethincity is relitivly the same as the rest of the subcontinent. punjab is in no way isolated so over the centuries there has been a constant flow of peoples in and out of punjab. the sikhs only controlled punjab for a very short time and even then they did not have a majority. the sikhs only controlled punjab from around 1716 until 1849 that is 133 years which is not very long in the large picture and the sikhs were only totally in control for less then 50 years. during the times that the sikhs did rule there were many other people besides sikhs who lived in punjab so they have just as much right to the land as we do. when the british took over they won fair and square, we lost in a war that we had started, we were not able to defend what was ours and thus lost it.
it would have been great to get a home land like the pakistani's (pakistan was probably one of the worst ideas in history) but things didnt work out that way because we did not have a majority in any region we occupied and when it comes down to dividing land up it goes to the ones with the majority.
for khalistan to now happen thousands of hindus and muslims would have to leave places they have lived at for hundreds of years ( even before the sikhs were ever around) and know body wants to repeat partition. either that or they would have to except theocratic rule by a religious group with only a very slim majority. where in the case of tibat many han chinese would have to move but most of them havent lived there for more then 50 years so it would not be so bad.
as far as all the support tibet gets it is because people actually know what a buddhist is, and probably know what a tibetian budhist is. most people in the west have no idea what a sikh is. there is no western conspiracy to keep the sikhs down, most of the west has no idea who we are. our land is not indistinguisable from the rest of india as tibat is from the rest of china. and the western government for the most part don't care about the tibetians or the sikhs most just want to trade with china and india and couldnt care less about their minorities the only real support tibet does get is from individual citizens in the west and from the tibetian diaspora and sometimes polititians give it lip service.
in summary, to the west, tibet was a peacefull nation living for hundreds of years with a unique culture and religion which was suddenly taken over by oppressive communists. to the west the sikhs are a small minority among hundreds of minorities who are trying to break apart the 'benevalent democracy started by gandhi a champion of non violence and a hero to many in the west'. the sikhs are just an after thought and people know as much about them as they do the marathas, gujarti's, kashmiris and all the other ethinic minority groups in the subcontinent. there arnt enough of us, we arnt known enough, and we don't have a majority ( and i don't consider a very slim margin a majority) and we never have, in the lands we claim to be ours. that is why we don't see white people waving khalistan flags and putting khalistan stickers on there bumpers
many of you might say im hindu rss etc but really im a realist and the only way we can ever hope to achieve khalistan is if we can see our selves through the eyes of others and not through blind emotion sparked by the longing for a home land.