[lvlrsSTI]

When it comes to renting out homes ...landlord share experience and then from those experiences profile the type of tenants they want. 

Race, country of origin, job etc are used to profile.

For example  some landlord may not want to rent to group of construction workers because they may dirty the house from construction site and so on.

But all these are judgements made to protect one's own assets 

The use of race, profession, country of origin, age group is just used in an assessment in which goal is to protect properly. Because race is used landlord is called racist...but I am sure profession, country or origin etc is also used.

I think the term "racism" and racist is now used too liberally. ...there is an angry hateful tone often attached to it.

In Sydney when Asians look for a place to rent, after inspection Asians are always put at last in the list, landlords prefer white Aussies. This is definitely racism.