Divorce is not something that everyone should be doing, and it is bad that the divorce rates are so high lately. However, if people were unable to get divorced it would probably cause way more problems, domestic violence, arguments, bad environment for the kids. So yes it is bad, but the lack of may be worse.
Divorce can harm children involved if it is done in a contentious and mean spirited way. However, in itself it is not bad or good. It is just a choice that must be made if relations are really strained with no hope of renewal. Divorce may even reflect an unrealistic expectation that society puts on legal marriage to be forever.
No kid wants their parents to get divorced. It rips a family apart. But, unfortunately, sometimes divorce is necessary. Sometimes a marriage just doesn't work out. Sometimes there is domestic abuse. Sometimes there is cheating. Forcing people to stay together when they no longer love each other would be bad for society and bad for families.