Old Saws and Scabs
Yes!
Get on with your own life and leave others to theirs. You will not get any more by denegrating others. Every one knows their worth and they don't need you to remind them.
If an instructor offers their time for nothing that is up to them, they do not need permission but when they do there are always strings attached, quite reasonably. All schools/clubs with the exception of a few particular set ups will wish to pay fees/wages to have, in return, a commitment from instructors.
The professional job of CFI and other full time and senior posts will be required just the same as will be the bulk of regular instructors.
As for the hour builders they will be needed too, once again as they always have been.