Student or Learner
Last week, a colleague of mine corrected a sentence I wrote. Below is the original sentence, followed by the corrected one:
a) Student welfare is the major concern of the Principal.
b) Students' welfare is the major concern of the Principal.(corrected by my colleague)
I don't think the phrase 'student welfare' is wrong. If I am not wrong, the word 'student' functions as an adjective, describing the word welfare. The whole phrase refers to the welfare of all students in general.
Please tell me if I am wrong or not, and give me reasons. Thanks in advance.