> 1) If you are busy protesting by blocking a street this causes you inconvenience
You only have a finite amount of bandwidth, and you have to decide how much to use for DDOS and how much for your own use, so, in a way, the analogy of street blocking still holds there.
That's true but with a physical protest you don't have that choice, you pretty much have to be all in (not to mention putting yourself at risk of physical harm by counter protesters or police etc).
Also I don't think where we're at the stage yet where losing your whole internet connection temporarily (or just having it slow down) are that much of an inconvenience to life.
If you have a 10Mb pipe and you could use 90% of it for DOS for an entire day without noticing much inconvenience (unless you want to use torrent or stream HD video).
You only have a finite amount of bandwidth, and you have to decide how much to use for DDOS and how much for your own use, so, in a way, the analogy of street blocking still holds there.