It's an impossible challenge for a celeb to be utterly lovely at all times and have absolutely zero people have something bad to say about them.
One grumpy look on a shitty day when they've got to go and slap on a public face and they really don't want to, to the wrong person, and that person is going to be horribly disappointed and tell everyone how awful XYZ is.
That said - Anthony Head is a fucking saint and I adore him, but I have known his wife for years (so have a lot of people in my field though so not really any big deal!).
I could dish the dirt on a lot of dog related telly types...
Graeme Hall is not very nice, also his 'qualification' in dog training is entirely self certified and a 'pay annually having ticked some boxes to agree you can do what you say you can do' affair. He's also very outdated and poor at actual dog training, but extremely good to camera and has the sheer, unadulterated arrogance required to do what he does.
Victoria Stilwell is very good, both in front of camera and at dog training/behaviour, far more so than the current TV show really demonstrates tbh as the format is rather shallow and 'shiny' and it doesn't show the depth of work that has gone in behind the scenes - but tv dog training is a tricky bastard, too much actual effective, kind dog training is basically boring as fuck and no one would watch it. SO it has to have some sort of frilly shit going on!
Linda Biscuits from Late Night Lycett is a sweetie, has never weed on a studio floor and never would! (Joe though... not so much and almost certainly would!)
I have never heard a single bad word about Paul O Grady and I have worked with people who worked with him on tv, both front of camera and crew and no ones ever said anything other than that he was absolutely lovely (and if people aren't you REALLY do hear about it from the animal peeps, we're not tolerant of people who are drama queens or arseholes around animals!).