While a lot of Christians (and Jehovah's Witnesses) often read these texts with approval of the death of the Egyptians (and others of God's "enemies"), Jewish exegesis isn't as forgiving or accepting. Too often these Jewish texts are judged merely by their Christian interpretations, whereas those of the Jews get ignored. The result is often like judging a movie by the words of someone who misunderstood the film instead of watching it on its own terms and perhaps listening to the commentary track of the film's producers to make sure you've got the correct understanding of it before coming to a conclusion.
To begin with, the narrative of the Ten Plagues is not taken as literal history by the Jews. Did you ever notice how often the Egyptians lose their animals to plagues? There is one plague where all the livestock die, but in the plague of hail there is still Egyptian livestock leftover to die in that plague. If all these animals died twice over, where did the firstborn of animals come from to die at Passover? With all the animals dead, where did the Egyptians get their horses to drive their chariots? Didn't they all die at least once? You mean after killing them three times over, those horses still came back to life in order to chase down the Israelites? If you ask me, that's some pretty poor delivering of us Israelites by God. First thing he should have done is made sure those horses stayed dead!
Starting to get the picture? It would take much too long for me to go through all the details (you could simply read "The Jewish Study Bible" which employs the JPS text of the Tanakh for a concise introduction into how these texts are meant to be employed by their authors), but there's a lot of "dying" that goes on in this narrative that doesn't really mean what JWs and Christians tell you it means.
You are judging the monotheistic God concept of Judaism not by its theology but by its legendary description of the Exodus (and it's not even the one we annually repeat on Passover in our Haggadahs either). And to make matters worse, you are using basically the same interpretation of this tale taught to you by a cult (of all things), and making a conclusion about God on that basis.
Mind you, I'm all for atheism. The love of my life was an atheist. Many practicing Jews are atheists. Give me an atheist for a friend over a theist any day!
But you might want to employ just a little more logic here. This isn't a factual story. We didn't get Passover from the Exodus (we were likely celebrating Passover before we were slaves in Egypt). If we don't read what's written in Exodus on Passover night when we reenact our Seders on the most holiest of our days, obviously something's amiss in the conclusions you may be making here on this thread. Ever wonder where our wine use comes from? Why the roasted egg? Why don't we paint our doors with blood on Passover like the Torah demands here? Exodus is far more complex than what some are reducing it to here.
I get it. You don't believe in God. You may be concentrating specifically on what JWs have taught, I get that. But you are also nevertheless dealing with cultural subjects which are currently under attack around the world right now in a new wave of anti-Semitism. A little differentiation may be called for. And I am sure that some here may be applying their opinions not just against JWs teachings but to this cherished part of Jewish culture in general.
Remember, don't judge the Jewish religion, it's monotheistic concept, or its text merely by what a crazy cult from upstate N.Y. taught you. If you're gonna criticize it, at least do it based on our own Jewish exegesis.