Those starting IBM straight out of school then sticking around for 10 years vs. people coming into IBM with 10 years of experience are two separate worlds.
For example: if you started IBM 10 years ago with an undergrad, you might have been offered $55k where I live.
Then over time, you might get 2 promotions and economical raises from software engineer -> staff software engineer -> advisory software engineer. You might work yourself up to $100k. However, they would motivate new grads with ivy league degrees with 100k offers. It made me physically ill at one point working in hiring and watching coworkers get turned down for minor requests for raises to amounts lower than what these fresh faces are getting before negotiations start.
If you want to hire someone with 10 years of outside experience, those people would command at least $150 - $175k, but IBM could get 3 college grades for the price of 2 experienced hires.
Thats what I mean about college grads getting paid more than more senior employees, while college grads are cheaper than experienced hires.
Those who worked at IBM for 20 years have less motivation to keep up with current trends and tend to focus on proprietary offerings they work on. As a result, college grads are better economical value since they come 'pretrained' with the new stuff. This is my theory why older people are first to go, especially in the short product cycles IBM tend to have.
A previous co-worker who still works at IBM has been there about 20 years and he pulls $140k... I have 6 years out of college so far and pull $150k + $15k bonus + 10% yearly RSUs at a listed public business down the road. Thats not an abnormal salary)