Talk about chintzy. $2 is no skin off my back, and it's worth the money to avoid long lines, but it just seems cheap. I used to always tip the porters $1 per bag so it seems as though that tip revenue is merely being diverted to the airline.
In leaving SF today, I also noticed that the self check-in lines, which used to be an oasis of short lines, have turned into the main economy check in line with a huge queue. Not an improvement. One shouldn't have to be an elite flier or paying FC/BC fare to avoid 1 45 minute wait, but then again I suppose I'm not the most price sensitive consumer and i'm willing to pay a little more for some semblance of service.