The defense is there to prove his defendants innocence and that he was not the one who did what they say he did to be labelled and assumed a criminal.
That is NOT the defense attorney's job (at least not in every case), and I think you have to draw a line between MOST cases and high profile cases. MOST cases are handled by public defenders and don't make headlines.
The primary job of a criminal defense attorney is to ensure that defendant receives a fair trial that meets minimum constitutional standards. The prosecution must prove guilt beyond a reasonable doubt. The defense does not have to -- and, in most cases, does not try to -- prove anything. Criminal defense attorneys do not, for the most part, ask the defendant, "did you do it?" What they do seek to do is try and poke holes in the prosecution's case. For example, was the witness in a good place to observe what she claims to have seen? The only time I sat on a jury was a criminal case for simple possession of crack. The defendant did not testify, and the public defender offered no witnesses. She did, however, cross-examine the heck out of the arresting officers, and this led some on the jury to have doubt about whether the officers had planted the drugs on the defendant. We eventually convicted the guy, but it took a lot more deliberation than I expected when we began, and that's because the public defender did a good job.
Of course, if the defendant is claiming, for example, entrapment, then he/she will have the burden of proving that. But that stuff doesn't happen all that often (and, as with a lot of legal issues, the general public doesn't have a good grasp as to what entrapment actually is).
the defense of criminals has gotten disproportionately way stronger than it needs to be compared to justice for victims.
I don't agree with that at all. Most criminal defendants plea bargain (which entails an admission to the crime), and most defendants who to go trial are represented by public defenders. By and large, PDs are good at their jobs, but they are almost universally underpaid and overworked.