Why so many unrealistic acquittals?
In the US, the conviction rate for cases that go to a jury trial is around 90%, and even the very best criminal defense firms lose the vast majority of their cases. That's just the way the system works.
So basically, The Practice follows the travails of the most successful criminal defense law firm by far in the history of the modern United States...
I don't know... suspension of disbelief is one thing, but this goes way beyond that. The problem is, many of the characters who are acquitted on the show would have absolutely zero chance of being acquitted in real life anyway.
Juries are not very principled in most cases. They will convict on dubious grounds all the time. Appeals to "the judicial process" almost always fail. Insanity defenses virtually never work once a case proceeds to a jury trial.
It's just not realistic.