Three points before we get into this:
Firstly, the independent article isn't representing the whole story. The bill that was passed creates a committee to look into potential constitutional changes to allow for expropriation without compensation.
Second, while the EFF may mention taking land from white people in their speeches, the bill does not target white people explicitly. It only mentions expropriation of land without compensation.
Third, the EFF are not the largest party in parliament, so if land reform is to take place it will be led by the ANC.
I'm going to tackle certain aspects of your question now.
To me it seems obvious that an impartial observer should see parallels between this new law and the Apartheid.
Okay, this is simply ahistorical. The apartheid was an institutionalised system of separation, oppression and exploitation by a small white minority over the majority of the population of a country.
White people still control a large portion of the wealth in South Africa today and most top executive positions are still held by white people.
Also, remember this potential land bill will not target white people, but target owners of land. It just so happens that white people still own the majority of land in South Africa.
Is there a rational reason for the West to ignore discrimination
against Caucasians?
South Africa has many economic albeit failed policies to empower black people, that can often come at the expense of white people. Things like Black Economic Empowerment encourage the placing of black people in top executive positions over white people. Would you want the west to intervene over such a policy? Considering the west has similar policies with things like affirmative action?
Therefore it seems logical for Western countries to react in a similar
manner to how South Africa was sanctioned
Please read the Wikipedia article you linked. Most governments were reluctant to sanction South Africa. It was only due to mass protests within western countries as well as the winding down of the cold war that gave room to western powers to engage in sanctions. Many ANC members were on CIA terror lists, and Margaret Thatcher supported the Apartheid Government.
Side note: I have some biases in answering this question.
I am South African, I am white and I am generally a leftist. I personally do not support the bill as it is aimed at farm land and I think urban land is the real issue in South Africa right now, especially in Cape Town. However there is a lot of misinformation going around about this bill. If you want news about South Africa, I would recommend publications like:
The Mail and Guardian (Huge exposers of Zuma corruption) - https://mg.co.za/
The Daily Maverick - https://www.dailymaverick.co.za/
and http://www.enca.com/