I think the harsh reality is that people have got used to what by any historical norms, are spuriously low interest rates. 2.25% or even 5% or 6% are still low by historical standards, although returning to those latter levels would doubtless cause enormous difficulty for many people. I guess understandably desperate to get onto the housing ladder, many have borrowed more than they can afford unless the rates stay as low as they have been. They've basically gambled that rates would never go up, or that their income would go up fast enough to cover it if it did.
Hopefully the rates won't peak as high as people are suggesting and only a smaller number of people will find themselves in difficulty.
And, BTW, just as an aside, I have been campaigning strongly on here for the BoE to NOT raise interest rates, whereas in fact, higher rates would be good for me because I have long since paid my mortgage off and would just get a better rate on my savings. But this can't be right because I am just a selfish **** etc.