There were plenty of changes I wish they'd made in the new PHB, and plenty of things I wish they'd changed more, but to their credit I don't think there were any changes I actually disliked. The only thing I really think was a miss was the option to just make a custom background. The cynic in me reckons that they did it this way so they could still sell additional backgrounds later on...
They puti it in the DMG because they want you to work with your DM on your background, which would both give the DM an idea of what it is ahead of time to better work it into the campaign, as well as make sure effectively anything custom goes through the DM first.
There were plenty of changes I wish they'd made in the new PHB, and plenty of things I wish they'd changed more, but to their credit I don't think there were any changes I actually disliked. The only thing I really think was a miss was the option to just make a custom background. The cynic in me reckons that they did it this way so they could still sell additional backgrounds later on...
They puti it in the DMG because they want you to work with your DM on your background, which would both give the DM an idea of what it is ahead of time to better work it into the campaign, as well as make sure effectively anything custom goes through the DM first.