No negatives huh- personally I see the vast majority of them as lazy but that is getting into a merit of games debate which would be kind of pointless to have right now. What I what I will say is negative is the general impact on cheats
in single player both in terms of button combinations and earning cheats
although EA's buy the ending to the game model seen in a lot of their games is also part of this. If I may steer it back to the lazy part though it has also had something of an impact on easter eggs, pissing around and similar ideas where things will tend to be given a token achievement instead- give me a lights show, a piece of new armour (bomberman 64 did this well although a slightly different system can be seen in some of the more nonlinear mario titles which is to say most of them after lost levels), maybe a new mode/cheat mode (see N64 goldeneye) instead of an achievement any day of the week.
Now of course there are examples of games that avoided this (borderlands did well with the experience bonuses for certain things), still had cheats
(GTA did OK here), used them to good effect (some of the borderlands DLC like the final boss in The Zombie Island of Dr. Ned) but that would mean people had to put effort into such things and I can not blame anybody if they were mandatory for phoning it in instead of getting something useful done. Granted this makes it something of a self fulfilling circle of nonsense as respecting achievements can not be done without good ones and nobody is really going to do good ones as a matter of course unless they are respected.
As a history lookback... unified system maybe (although it is not a good one for a lot of types of games) but I have seen milestones and breakdowns thereof in RPGs, puzzle games and and similar titles for years now (rpg game with a diary? and although I have yet to get as far as to see it for myself the trial in chrono trigger?) and for as long as consoles have had clocks onboard it has been tied to those as well. It would take no effort at all to punt some of that to an XML format the dash could read and if XML was used in lieu of system wide achievements (game achievements I have no real problem with or better something like the borderlands experience boosts I would even encourage).
I have probably mentioned it in the past but if there was a conversion rate to the points/money used to buy arcade/wiiware/dlc that would be a model I can definitely support. Of course that would probably* bring the second hand and rental market "debate" full circle and that would probably end badly for those that like that market if full price games still exist at the time and as nobody looks to be taking that leap any time soon.....
*it does not have to and could fall into the building an online community, enhanced demo, older games instead of second hand or just plain good practice but the last few years have not left me an optimist here as far as mainstream consoles are concerned. Hopefully someone in the free to play world or mobile phone games world does something interesting here and many have recognised preludes to this (constant free DLC/updates makes for continued sales is well known at this point).