I would imagine it is disabled because it is illegal to record the call unless the other party consents and the great majority of people who use this WON"T be asking for consent before recording a convo. It is a serious charge to do this, my old boss almost got sent to prison for doing it about a year ago.
That is incorrect. In the US, recording a call is legal if at least one of the parties involved in the call are aware they are being recorded; even if the aware member of the party is the one doing the recording.
EDIT: Federal Law in the united states requires only the consent of 1 party of the conversation for recording to be illegal. While most states have adopted laws similar to that of the federal law, 12 states have restricted it to "all parties" in most circumstances. Those states are California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania and Washington.
END EDIT
That means you can record all calls you take part in, without consent from any other party on the call. However, you cannot record other parties speaking to each other if you are not on that call (ie wiretapping).
I had Call Recording apps on my Windows Mobile HTC Touch Pro. However, they only got both ends of the conversation if you had the speakerphone activated as they could not access the voice coming across the internal earpiece. It was ok, but normally a pain to have to use the speakerphone. It was a hardware limitation of the Touch PRO.
I imagine it's a similar issue with some of the Android phones and believe that I recall reading such accounts across various forums.
Cheers.