I see it as counterproductive because it makes the task at hand harder than it needs to be or impedes the goal. Yes, many mistakes have been made. A rational person with any perspective understands that the general public doesn't have all the details of what takes place in a given situation so why undertake measures that have the potential to backfire given that the media isn't likely to be on your side. Legally states and cities aren't required to assist ice so why not spend the necessary time to negotiate the cooperation needed to avoid the scenes that have played out. Has any of the chaos helped in achieving the goal? When people like me who support deporting those here illegally go "what the fuck are you doing", then you haven't managed anything to do with it well.
Cruel isn't a word I would use personally though I can understand how people opposed to deportations would go there. I have spent enough time in the business world to know that the vast majority of people want to do their jobs the right way. When they don't it is usually the fault of management which is what I perceive as the majority of the problems with ice. Wrong plan, wrong tone, wrong training, wrong leadership, etc. I'm sure there are a few rogue ice cops who get off on trying to inflict as much harm as possible but as with most jobs those are a very tiny fraction of people. I suspect that your concept of cruelty goes beyond individual cases and includes the intent to deport many of those here illegally.