I've had 50% pay raises that were nearly matched by the current employer. My last manager literally said the words, "What if we offered you a big bag of money to stay?". I left.
Now I work at a place where people stay literally until the die, 10, 15, 25 year tenures. My coworkers are mediocre. I'd say it's a mixture of laziness and sometimes maybe just incompetence.
It's a two fold problem. Employees that stay this long do not progress in their careers or learn new skills. I've learned next to nothing in my 5 years here. Employers that don't create churn in their workers create numerous problems. If we didn't hold a monopoly in our field, I'm sure we would have been bought out and had mass layoffs by now.
