I'm not sure why God doesn't cure amputees. But, lately Medical Science has made quite the breakthrough on this. Some believe that cloning is the way to replace a lost limb. There are also some great orthotics. But, nothing can replace a authentic human part. The WT answer of course is wait for the Kingdom, and that will be the answer to your prayers. In the meantime we get old and die, people starve, war breaks out, desease, etc. It's hard to be positive when you dwell on such negatives. Sometimes people develope a chip on their shoulders and look to blame God for this mess.