Wages
Over the last 13 years our wage increases averaged 1.5% (per year), well below the 2.75% inflation average over the same time period. McMaster sessionals are considerably underpaid relative to sessionals at other leading Ontario universities.
Job Security
The employer has made their point: they prefer “flexibility” over job security. Your precarious working conditions and your experience teaching is of little concern to them. They would rather be able to replace you with someone who they think is better than you.