To be fair they're not cutting bursaries, just removing the requirement for universities to give as many as they do. Given that a lot of universities go above and beyond in this regard already, it probably won't make a whole lot of difference. Additionally having seen a lot of people who are in the bracket where they're getting these kind of bursaries, and in fact being in a similar situation myself albeit with less maintenance money and no bursary, they didn't affect anyone's choice to go to university and are more seen as a bonus. The basic loan for people with parents in the required income bracket is more than enough to live on, let alone with bursaries on top, though I could perhaps see the benefits for sportspeople and those at unis with more expensive living costs e.g. the London unis, Durham, Brighton, etc. The biggest deterrent I've seen is the lack of understanding of how you pay back your loans rather than the amount of money itself.
Yes, it does benefit high earners more as they're now more likely to pay it off, but at the same time this applies to middle earners also.
Essentially there's no real way of winning. Cut fees and higher earners benefit at the cost of universities or students from poorer backgrounds, and some of that burden will also be pushed to internationals. Increase fees and you help the universities but put off people from poorer backgrounds, punish higher earners, probably punish international students as universities will want to maintain the premium cost. Eliminate fees and you either have to implement a graduate tax which comes with a bunch of problems or you put the burden on the taxpayer, and you likely end up reducing the amount of money going to universities at the same time.