It's totally fine if they raise rent in step with inflation. It's the dramatic raise that's the problem; the tenant will have to choose between paying the extra

It's totally fine if they raise rent in step with inflation. It's the dramatic raise that's the problem; the tenant will have to choose between paying the extra cost of rent, or paying the extra cost of moving out, and they have no way to avoid that cost, through no fault of their own. Someone could be forced out of the home around which they have built their entire life.