Story is…
No profession can have that many members with so few who need to be sacked.
The training for, say, GPs is more strict than that for teachers and more are ‘struck off’ despite there being a similar number of each (according to google).
Sacking doesn’t just need to be for gross misconduct, it can be for failing to work to the expected standards. Although remedial training is used, there is less of a link between job safety and competence than in other professions.
My fiance is a Primary School teacher, and I know that there is an acceptance that some teachers aren’t that good. The training does little to remedy this, yet they simply don’t progress rather than being sacked.
I can’t speak for Secondary teachers (and I suppose am not in an position to talk with authority on Primary teachers, just offering my opinion) but there are some who enter the profession to be educators, and are a credit to their schools, whilst others see it as an extension of childminding and shouldn’t be left to teach and inspire a love of learning in our kids.