Rashi (11;9) explains that the generation of the disunion lacked belief in Hashem whereas the generation of the flood didn't--and yet, it was the generation of disunion that were saved. What's the reasoning for this? Rashi (11;9) explains that the generation of the disunion were saved because they behaved with love and friendship among themselves.
However, if the generation of the disunion had peace then why did Hashem disperse them everywhere (11;8) and give them different languages (11;7) thus destroying their personal relationships?
Additionally, the Mishna (Pirkei Avos, 5;20) states that any argument that is for the sake of heaven should be everlasting. However, what exactly is the reason why we want good arguments to never end? Isn't it better to not argue at all?
Rabbi Yochanan Zweig explains that the purpose of meetings is to bring together different people with different perspectives. Rabbi Zweig explains that when people are different they are able to respect each other because they could each contribute things the other can't. When 2 people are only able to contribute in the same areas (for example, when 2 people have the same exact jobs) then they become rivals because they each can't give things the other can't.
Further, Rabbi Zweig explains that in an argument for the sake of heaven, each person learns from the other. Therefore, not only is an argument for the sake of heaven not bad, but we actually need it to survive with one another because it creates a bond between us and our fellows allowing us to come together and gain from one another. If we don't have any arguments then we won't truly realize how we could all gain from our friends. Thus, the Mishna (Pirkei Avos, 5;20) states that all arguments for the sake of heaven should never end.
Lastly, Rabbi Zweig explains that the generation of the disunion got along but they were all similar to each other so Hashem gave them different languages in order so that they could all have the ability to share knowledge with their fellows. By making them different Hashem was helping them get along even better because they would all be able to respect their friends even more for their own unique qualities.