DRblank is completely correct, it is absolutely ridiculous that manufactures who use Android as their OS take so damn long to release an update. It's the individual manufactures fault though, not Google's, Android. Google releases the source code for Android in a very timely manner and even update their own devices fairly quickly, normally within the same month of a new Android release. The problem is, In a attempt to stand out from the rest, mobile makers add their own flare to Android as well as custom software. With this approach the manufacturer has to completely migrate their software and custom desktop to the new Android version every time it's updated. This takes time but not 6 months. Another problem is manufactures seem to ditch even their best handsets after two years with no further updates. Now the custom ROM communities like CyanogenMod has done a wonderful job in picking up the slack but manufactures cannot/should not rely on this community to pick up their slack.
As a programmer and an overall computer tinker, I use custom ROMS from the get go so I enjoy the latest updates and most secure phone possible, the normal user should also enjoy these benefits. Get off your butt's Android phone makers.
Show me the history of a specific OEM Android phone release date of their updates and compare it to Google's update release date. Please show me proof it doesn't take 6 months. Google released 4.2.2 in February and when did Samsung start releasing updates for the S3? It wasn't until when?
There are models of OEM phones that STILL can't get the 4.2.2 update and that's more than 6 months old update. These custom ROMs are not what the majority of users do, the majority of users use what the mfg has released.