Students who do not meet minimum standards are often guided out. Similar practices occur in CIS, HKIS and other international schools, and these practices are standard in local schools.
I find the whole post over the top and reeking of sour grapes - this student has clearly been disappointed in some way, personally or academically or socially, but I do not think you can take one students' view and use it to judge a whole school experience.
CDNIS has just posted their IB results in their website. And I freely acknowledge that results are not everything, but the school does have a rich and vibrant cultural and sporting life and students are actively encouraged to participate in these programs, right through their years at the school.