This is a good question. Some amount of warming may be (have been) good. Temperatures had been dropping slowly for the last 8000 years since the height of the current inter glacial. Reversing that trend was probably a good thing. At some point the consequences of added warming will (or possibly have) become detrimental. Small changes in global temperature can have large impacts regionally. As the globe warms, local climates will change more dramatically than the global mean. There will be winners as well as losers.
As others have pointed out, 0.7C doesn't seem like a lot, but it represents a rather large amount of energy. Small changes in global temperature have been seen to have drastic impacts - including moving the world between glacialinterglacial states.