This has really set me off. I'm in a fortunate position of having the money to pay the fees. I don't like it, but I can.
There are a lot of couples out there that combined just qualify with the £18,600 requirement. At £1,875 for ILR, that's more than 10% of their gross annual salary. Seriously, it is all about money. I bet there is a big rise in illegal overstays as a result...
See, this is exactly the thing. This government (and the people who support them) bang on and on about reducing illegal overstays, and wanting to ensure that immigrants 'integrate' into Britain. Yet every change they've made ensures pretty much the direct opposite will occur.
Making people wait five years instead of three to achieve some modicum of security (in the form of ILR) means that you're not fully secure in your standing for a very significant chunk of time. Why fully integrate if you feel that it might be a good idea to keep one foot in another country, culturally or otherwise, just in case.
Moreover, it creates an inherent power imbalance in a relationship -- relying on someone else for your legal status is potentially extremely precarious. Creating a system that casts that shadow (however minimal) over a relationship does not give the migrant a firm foundation from which to integrate.
Then you add a big ol' portion of financial concerns. Spending five-plus years stressed about paying extortionate rates (as opposed to being generally irritated, which is my lucky privilege) is absolutely toxic to being able to jump in and participate in British culture (let's face it, going places and doing things costs money). Maybe the idea is that the migrant will essentially have to work and/or find a higher-paying jobs -- but then you get to be the 'immigrant stealing jobs from Brits' -- so it's really a no-win on the integration front.
Top it all with the NHS checking your paperwork, the 'spot checks' I've seen at London tube stations, landlords/agents turning people away for not having a 'native' accent ... yeah, migrants are feeling so at home. This government has done nothing but codify that feeling of division -- and, cynically, I think it's been deliberate, so that they can turn around and say 'See! They're not integrating!' and make the system even more hideous to the already-marginalised, in particular the working class and the poor.