The government-ordered conversion from analog (NTSC) to digital (ATSC) occurred in June 2009, and was directed at over-the-air reception only. The government did indeed offer coupons to discount the cost of acquiring ATSC-to-NTSC/composite video converted boxes, which would enable older televisions to still be used, for display of the video (though not for the tuning of channels - that was done in the converter box).
This conversion was not directed at cable (or satellite services). Since cable was never subject to the kind of atmospheric interference that over-the-air reception is regularly subjected to, it uses QAM to transmit digital television signals, instead of the less efficient (but more robust) ATSC. Cable converted many years ago to a hybrid analog/digital approach, providing some channel via both analog cable and digital cable signals, so customers with older televisions could continue to use the analog service without a converter box, but providing all services via the much more efficient digital signals.
Indeed, while many upstart services, such as FiOS and U-Verse, and the satellite services, never offered this analog/digital simulcast advantage to customers, typically the legacy cable company continued offering channels via this less efficient analog service, even when the scarcity of bandwidth got so tight that offering the analog resulted in substantial customer disloyalty, with the most profitable customers switching to the upstart competitors, not caring that it means QAM converter boxes for every television. Essentially, the legacy cable companies took a very big hit to their bottom line in the interest of trying to keep things the way they've been as long as possible.
However, the competitive pressures have become too great: A cable company that cannot boast 200+ channels on the expanded tier is going to lose far too much money. And the only way to fit more channels in the same wire is to use the bandwidth more efficiently, in other words, abandon analog service and rely solely on the digital service. So that's why you're seeing cable companies move more and more of their service onto digital service, for which you need Digital Cable Ready (DCR) equipment (see below).
A word about the term "cable-ready"... "Cable-ready" indicates a television that is ready for analog cable service (i.e., the old kind of cable service), not digital cable service (i.e., the current kind of cable service). The term that indicates that a television is ready for digital cable service is "DCR" (digital cable-ready). Alternatively, the term "CableCARD" also indicated readiness for digital cable.
Now they want me to get the digital box in the other rooms to be able to get these channels!
