Many people believe that wire cages are bad for rabbits, with the one reason being that they can cause sore hocks, which are sores on the rabbit's feet.
Sore hocks are very possible in wire cages. Actually, they are very possible no matter where the rabbit is housed, and even more so in solid bottomed cages. I have heard of more cases of sore hocks on wooden hutches soaked with urine, than in wire cages.
Most rabbits have thick pads of fur on their feet, so wire cages don't bother them. The fur on their feet it thicker than any other fur on their body. It's a completely different texture. Some breeds with thin fur on their feet, or really heavy breeds, such as Rex or Flemish Giant, might get sore hocks a little easier. But it's easy to prevent with a resting mat or just a consistently clean cage.
To keep my rabbits happy and healthy, they need a clean environment, so it's essential to keep their cages at least mostly clean. Luckily, rabbits don't need to need to live in a sterile environment so that makes my job a little easier :) Wire cages are the best way to keep our rabbits from living in their own filth, unless you don't take care of it and allow the urine and feces to pile up in the cage.
No matter where your rabbit is housed, as long as the cage is kept clean and tidy, your rabbit should never get sore hocks unless they have very thin fur on their feet or they are very heavy.