I wouldn't call it a shallow dismissal. If you used Libreoffice you already know the current state of it. It is slow, buggy, way behind in features compared to MS Office and the UI is a mess. If I tried to take Excel away from my co-workers and gave them Libreoffice Calc there would be a riot.
I introduced libreoffice at work in 2013 while reducing Microsoft dependencies around the office and we had success migrating from Excel and Word for about 20 employees.