I like moving over for motorcycles. It's a little thing, but costs me nothing and is totally available as a recognition. Maybe it's like saying, "I see you." I had wondered if it was helpful. Now that you told me it's not necessary, I guess I'll continue doing it anyways.
I think I may have given the wrong impression: I definitely appreciated it. When I said it's not necessary, I was distinguishing the act from legal acts that are necessary. For instance: a car waiting for me to take my turn at a stop sign cannot be evidence of the driver "showing consideration" since even the inconsiderate may yet prioritize adhering to a legal requirement.
Making it easier for me to lane-split on the other hand is not required of the driver. If they are doing it, they are doing so entirely optionally and consequently it is evidence of their being considerate.
When lane-splitting I appreciated the move over for the following reasons:
* I know you can see me
* It is more comfortable with more space
* I know you are willing to look out for other motorists => if a thing happens unexpectedly right in front, the spot I'm in next to you is safer than standard.
Related; when I'm driving my car, and I see a bicyclist riding on the shoulder, I like to leave tons of room as I pass (when I can). "Look at me! I'm a nice considerate guy! I like cyclists! I'm leaving tons of space! I respect your safety!"
On the flip side, when _I'm_ the one on the bicycle, and some car goes half out of the lane to pass me, I think "geez, you don't need to give me 20 feet of space, I'm not some drunk idiot, I can ride my bike in a straight line!"