You do lay off at that level if there's a mis-match between what a company is wanting and what the person was hired to deliver.

If Microsoft's "evangelist" roles are changing, it makes sense to dismiss those folks who previously worked towards those old objectives, since those objectives are no longer being targeted.

One is 'fired' due to incompetence. Another is 'laid off' due to a change in company priorities, direction and resource allocation.

Thats simply not true. I know a guy who was the president of a division with >80m in revenue a year, and was "laid off" with 5,000 other people after 28 years with the company and never a negative performance review. His boss went to bat with finance people but lost. There is a formula and sometimes it says people at level X can't be paid greater than Y, and if they get paid greater than Y, they are laid off. Often the reason they are paid greater than Y is because they are good at the job. Not a smart way to do layoffs, but becoming more common because it is easier to fire top down than bottom up a lot of times.

They do lay off whole groups in which case you have a bunch of managers and vp pondering what to do.

Though I'm sure we all know of situations where "layoffs" are used to get rid of problem employees because it's easier than a termination for reason.