To me, bicycles have all the downsides of a motorcycle except for cost and reliance on fossil fuels. Motorcycles are in my opinion safer in a city setting IF you ride with self control and vigilance (motorcyclists seem to self-select for unnecessarily-risk-taking types of people, but you don't need to be among them), due to the convention of wearing more protection Most bicyclists wear just a half helmet, if that. A loud exhaust can also make you more noticeable to cars, I'm not going to say loud pipes save lives but in close proximity an exhaust can be the difference between a car noticing you and not. Not to mention you get to wherever you're going much faster since you can ride at car speeds and still lane split.
To be fair, the speed plays an important factor during an accident, as accidents at higher speeds tend to have dramatically more severe consequences. The bicycles rarely reach normal motorcycle operation speed, and while motorcyclists tend to use better helmet, not that many of them actually follow ATGATT religiously (mostly those that have been in accidents themselves).
Generally though I'll agree with you that motorcycles are safer in cities than bicycles, but for a different reason -- motorcycles, unlike bicycles, generally ride along with car traffic on roads, and so car operators are more likely to see them, as they only appear where car drivers expect other cars. Many bicyclists have an unfortunate habit of riding on a sidewalk, which is very, very dangerous. Having brighter head and tail lights on a motorcycle, and blinking indicators definitely helps too.
