Ethics committees generally do not turn down research because they think it's a bad idea, but because the processes in place to protect the subject are sub-standard. In the example linked, that would probably be a heavy-duty human subject study subject to rigorous controls. An MA student has perhaps six months to research, write up and hand in, which (together with being an inexperienced researcher) would certainly raise warning flags.

Also, Bath Spa University is a relatively small, relatively new university with a less established research tradition than most of the UK's universities. It wouldn't surprise me if its ethics committees were less confident too.

None of which is to say that the student isn't right, just that we currently only have his word for it and the university is quite correctly saying nothing. But I'm pretty sceptical.