And of course the new smart system will enable parking enforcers to give you a ticket more quickly and efficiently as they will certainly have devices in their cars that indicate immediately when any meter in the neighborhood expires while a car is still parked there. I suspect this is the major motivation.
I can't find the article now, but there was something here a month or so ago about the new parking meters in San Fran. I believe you'll be able to add time to your meter and get alerts that you're running low via mobile phone with these new meters.
True, not all tickets are written for meters, but it's clearly in the city's revenue-earning interest to make it more difficult to legally park and write more tickets. And since a parking meter earns $55-65 with a ticket but only $2-3.50 for an hour of legitimate parking, an entire day or two of legitimate meter use earns the city exactly as much money as a single meter violation. Some municipalities--Seattle, as I recall--expressly prohibit paying a parking meter that isn't yours; the only reasonable rationale for this is to increase ticketing rates.