On what basis do you say these are rare? My experience as a cyclist differs strongly with your statements.
Many drivers don't seem to realize that cyclists take very different paths than drivers do. You might be thinking "where I drive, these exceptions usually don't apply" but you should instead be thinking about where cyclists ride. Yes, these paths do intersect, but a cyclist will typically pick lower stress paths.
Let's take my commute as an example, starting at my home:
1. Bike lane until I have to make a left turn. I take the travel lane to make the turn. Note that as far as I'm aware, using the left turn lane (i.e., taking the lane) is required by law, not merely allowed for cyclists. This is because turning left from the far right is obviously dangerous. Do you think left turns are rare? I don't.
2. Short road segment leading to a stop light. I take the lane here because the speed is low.
3. Right turn onto a road with signs and road markings saying that cyclists can take the lane. Despite the signs, I get harassed by road raging drivers here much more frequently than I'd like. (The reason for the signs seems to be a reminder of the previous #4 to drivers. The single lane is perhaps 9 feet wide and there are parked cars on the right. Definitely unsafe to ride far to the right. I've been nearly doored riding in the center of the lane here. But all of this is irrelevant, as I don't need to invoke #4 to ride in the lane center here.)
4. Three stop lights in a row. Again, I take the lane because I'm no slower than anyone else.
5. 15 mph speed limit for about 3/4 of a mile until the destination. I take the lane because I'm usually going faster than that. This path includes both left and right turns.
Often during my commute I'll pass other cyclists who are going slower than I am. It's not uncommon for me to pass motor vehicles too, especially in the 15 mph part.
So my commute includes all of these aside from 4, 5, and 6. I can't be "lumping #4 in for all cases" here.
I don't take the lane for my entire commute. But for the 2/3 of my commute that doesn't have bike lanes, it's easy to legally justify taking the regular travel lane.
And to be clear, here's my agenda: Cycling safely on the road. The main obstacle I see is dangerous drivers, and sometimes the solution is to take the lane. If you don't like that, encourage your fellow drivers to treat cyclists nicer.