Sounds as if you're implying that Zimmerman and Johnson are unprofessional. It's not like Zimmerman hasn't made those types of throws throughout his career. What about the great plays he has made recently? As for Johnson, that ball was scorched. He's lucky he got out of the way of that one in one piece.
Not unprofessional, just unmotivated, flat. Zimmerman has improved his throwing a lot this year, but as Dibble observed, it's simply a lack of focus when you're making the easy throw not under pressure.
On Johnson, he's had a number of opportunities in the last week to make a good defensive play, but has failed on every one. He even overran a pop fly and dropped it. Nick has been my favorite player since the team moved here, but I am disappointed in his defense this season regardless.