Hmm, is that true? I mean qualitative research is often more humble than quantitative, they don't claim to have found general truths. (OTOH, they do sometimes implicitly *imply* that their self-ethnographic wibbling/highly selected anecdotes/whatever have profound universal lessons.)

Fixed

My experience tells me otherwise.

See my earlier comment: 20% of a big number is a big number.

You are assuming that they are doing what their paperwork says they should do. What makes you think that? Experience leads me to doubt it.
If student visas are really long-term immigration visas in disguise, then the public is being misled by pretending otherwise.

Yeah but they are supposed to be primarily studying. But I think many are not and it is being used as an immigration/working route. The fact that UK universities are desperate b/c the gold rush has ended does not help.

My experience is that many are working while they are supposedly studying. Also, 20% of half a million per year is quite a lot.