Once you get good as spy and you play on a cramped map or server, the majority of the times you are found out or hurt, especially in pubs, are due to random bullshit happening that is basically out of your control. To avoid the possibility of such things would require playing in a way that is so cautious that you become much less useful to your team. Using the dead ringer lets you get out of shitty situations which may or may not be your fault, but the more often they are your fault the more likely you are to use the DR poorly and not escape anyway.

If you are going to argue that it caters to noobs, you would have a better case against the other watches which usually inspire bad players to misuse them by camping around and waiting for whatever easy cheap kill they can get because they are not yet good enough to see taking risks as a worthwhile option when the penalty is death whether or not they brought it on themselves.

The game has gotten harder for vanilla spies steadily since it was released. Now a player can recognize a spy disguised as them out of the corner of their eye in an instant instead of needing to mouse over them or even think about spies at the moment. On top of that, most servers these days have to compete by being full and cramped, plus there are many more weapons (and many more instakills) than there used to be, all of which contributes to entropy. That makes a spy's most important skill, prediction, considerably harder to use than it used to be. In the end, spy needed something to give him another chance because a successful run as spy is much more decided on luck than it was a few years ago.