Originally Posted by xtaz:
“Orange/T-mobile are currently in the process of replacing their entire 2G network with brand new kit including stuff like more sensitive receivers and antennas which should increase coverage. 2G's not going away for a while as the coverage of 3G (and probably 4G) are no way good enough to replace it entirely. And also there are a large portion of phones still out there which are 2G only, plus things like GSM modules in vending machines etc which are 2G only.”
I don't thing the coverage reason is that valid really.
The main reason 3G coverage is usually worse than 2G is simply the frequencies used. 2G networks are on a lower frequency, so travel further and penetrate buildings easier. With 3G now being allowed on former 2G frequencies, and with 4G having the 800Mhz band to be used, coverage of the faster networks should start to match the coverage of 2G networks in the next few years.
However, your second reason is the big one. Many phones, even some brand new ones, are 2G only. Especially the very cheap PAYG ones that people like my father use. To turn off 2G would just be commerical suicide considering the amount of people who still use it.