Ton of ways. First off many work out to be able to defend themselves, however it is a very ineffective method of self defense compared to how much effort is put into it. Second off if you get too bulky then you will become less athletic and being athletic is more useful than being strong IMO. Technically the only point is aesthetics and I prefer to look somewhat slim than bulked up. Also by working out I mean lifting weights, not running, sports etc. Those activities are great and get you fit. I guess I don't see the point in repeatedly lifting large pieces of metal. However if one DOES want to have strength and endurance, physical labor is much more effective than working out.
I might have to sue you after reading this, because my eyes are rolling so hard I fear I may have severed the optic nerves.
Being strong in an of itself isn't necessarily the most effective self-defense training, certainly, but I imagine that it makes you a more effective fighter than being weak. Of course there's also the psychological effect; if you look tough as hell, fewer people are likely to mess with you (although there are gonna be people who want to try to take on the toughest guy in the room, but I don't really live my life expecting to be in fights regardless of how I look).
Perhaps there are huge weightlifters who are also quite fat and out of shape. Well, it's easier to make strength and muscle gains on a caloric surplus, so these people might be bulking, or they may just generally be more interested in being big and or strong. Even if the only point were aesthetics (which is a foolish estimation), believe it or not, it's going to be a personal decision what people want to do with their bodies, and they might have different aesthetic goals than you.
Sports can be great fun, but I've heard it preached that if you want to be safe, you should get in shape for your sport as opposed to playing your sport to get in shape. This is going to involve exercise that will likely involve some weight training. Weight training leads to stronger muscles, joints, and bones, which I imagine would all be incredibly beneficial for someone who wants to be able to move, change direction, and stop quickly. Furthermore, weight lifting IS a sport. It's in the [censored] Olympics! On top of that, there's powerlifting. Strongman competitions may not be a weightlifting sport in and of itself, but you can be damn sure there's some overlap there as well.
Anyway, if YOU want to be skinny, lean, "toned" or just don't care, more power to you. Just try not to be so ignorant about what other people might be choosing to do.