As a general rule, alimony is not for life. It decreases over time until it goes away. How quickly depends on how long you were together and what drove the income disparity. If she worked crap jobs to put you through school for ten years, then you ditched her for a young co-ed after you become a professor, you'll be paying for a while. If you earned more coming in to the marriage and both continued working for two years of a failed marriage, alimony will be non existent or very short lived.
I'm nearly 50. I've seen plenty of marriages dissolve in my time. I have never seen any real injustice in terms of alimony. What I've seen is several men who were pissed that they couldn't just keep 100% of what they built together as a couple and a woman (the big earner of their family) who got screwed over because she didn't bother to do what her lawyer told her. Obviously anecdotal here, but I think this conversation is driven far more by fearful young men with ego issues rather than any sort of reality outside the odd corner case.