Global demand for meat is at an all time high and with a growing population farmers will struggle to meet demand in the (distant) future. We'll need to come up with something to meet the demand for meat, this seems like it could be one solution.
Lab grown meat isn't exactly a new idea though, it's one of many proposed solutions such as eating processed insects (which provides ten times more protein than rearing cattle does per food unit), taking synthetic supplements, cultivating more protein rich crops, etc. We don't really have to worry about taking these approaches for decades though, but it's worth getting them right now instead of finding out about potential problems later.
As for people saying it's disgusting, take someone from 100 years ago and tell them about how the food we eat today is produced. They wouldn't touch it. We may feel funny about eating this, but the next generation wouldn't.