There are undoubtedly parents who are problem for teachers ranging from disinterested to over invested. There will also be parents with 'nasty' personalities that are rude and threatening who are probably as nasty to shopworkers, hospital staff etc. In the same way there will be dedicated teachers, poor teachers and individuals that are just not very nice - teaching qualifications do not make people morally superior.
But one of the groups of parents that are a problem for teachers are often those with DC going through the long drawn out process of diagnosis for dyslexia, dyspraxia, ADHD, ASD etc. I can understand that teachers don't like to be lectured by those less well informed but equally parents acting as advocates for their DC are dismayed when teachers think that they know better than experts (EP, SALT, OT, community paediatricians etc).
This is usually not down to the individual personality of the teacher but seems to be a required whole school policy which leads to teachers not working in partnership with parents and ignoring professional recommendations. These are requirements of the job. At worst this leads to falsifying records, giving false reports to investigating medical staff, blaming parents (secret emails to LA, malicious reports to SS) to avoid the child receiving support/EHCP or if this is granted, non-delivery of statutorily required support.
DS1's primary school were a nightmare and insisted he was fine. They no doubt thought parents were a nightmare. The difference was that being a polite but insistent parent was fully justified whilst there was no justification for their behaviour. Their actions delayed diagnosis (ASD, dyslexia, and 6 others) and resulted in School phobia. He was 12 before SS was agreed following failed secondary transition and that placement broke down a year and a half later. He has barely left the house in the last 3.5 years.
He was failed by the whole education system but individual teachers played their part in that. I doubt they loose sleep over it now he has left their class/school. On the other hand I am now a full time carer and he struggles to survive each day.