It’s hard to say which is worse: spending the evening braced on the sofa, remote control in the emergency position to hit mute, or trying to deflect the horror onscreen by pondering how the BBC can create such gruesomely realistic scenarios yet never make blood look entirely convincing. Neither works, of course. No matter how swift the person operating the controls is, hideous images and sounds have already got under your skin. Then they return, deep in the winter’s night, to creep you out.

Like other viewers, I watched the first two episodes of the new Luther fully prepared for violence. I gave up on earlier series but thought it worth another go. After all, much has been made of the fact that the scriptwriters took on board criticism that it was always women who were being carved up. Idris Elba, aka Luther, says he helped redress that imbalance.

Well, God help us all if the latest storyline is meant to be an improvement. Admittedly it’s not young women who are being turned into living pin cushions as a sexual deviant gets his thrills, but does it make it better that most of the mutilated corpses are those of men?

Not remotely. The level of macabre detail was little short of horrific. It’s as if, denied the opportunity to focus exclusively on how vulnerable women are when psychopaths are on the loose, the writers thought up the nastiest things they could do to bump someone off and still get it past the censors.

Given its slick, droll script, perhaps we’re being encouraged to see the torture and murder of the victims on Luther’s beat as cartoonish: Tom & Jerry for grown-ups, perhaps, or Home Alone for baby-boomers; except that the killer’s profoundly warped psyche is not just gross but also seriously disturbing.

Why would anyone want to think about things like this when they switch on the TV at the end of the day for an hour or two’s entertainment? Turning instead to an Agatha Christie adaptation for respite and olde-worlde pleasure – or so we supposed – was to be met with a scene of masochism so bloody it was like stumbling into a field hospital. It was also ludicrous.

Completely unnecessary for the plot, this was cruelty and self-abasement for the sheer bloodlust of it. Interestingly, the actual murders on which the story hung were tastefully shown. Perhaps the writer and producer had rationed themselves to one gloriously gruesome scene and put their all into that.

It leaves you wondering if there’s a senior figure in BBC drama who has an agenda – or a problem. Otherwise, why show such depravity? Where’s the enjoyment or wonder in that? Television is beamed into people’s homes and can be stumbled upon or watched without active thought or informed consent. Watershed hour is the new midnight, when commissioning editors go on the prowl, like Jack the Ripper, to stalk and catch viewers. Nine pm – when children of six and seven are often still up – is a meaningless distinction for youngsters in their own rooms, or people who find it distressing to see graphic depictions of brutal death or mental illness or psychopathy, but catch sight of it nevertheless.

I know. It’s as if Mary Whitehouse has come back to life, wagging her finger with disapproval. Yet I don’t consider myself exceptionally squeamish. Deadwood and The Wire, The Sopranos and Boardwalk Empire, Fargo and Ozark were enjoyable, even though there were parts where I had to look away.

These days, most of the films watched in our household carry warnings for “bloody violence” and “injury detail”. Experience teaches you when to avert your gaze.

How worrying is that? Unless your taste runs to rom-coms, period pieces, soaps or light comedy, watching drama on TV requires a strong stomach or lightening fast reactions. The schedules are saturated with gore. It is bad enough getting to the end of the nightly news bulletins with their warnings of the disturbing scenes they’re about to show. Could it be that the remorseless warfare and conflicts, disasters and destruction we’ve witnessed these past 20 years have altered scriptwriters’ minds? Or – more frighteningly – is it we viewers whose outlook has changed?

If grisly dramas led to such universal revulsion that viewers switched off in droves, the Beeb and others would soon change the bill of fare. Since there seems no end to this trend, it would suggest most like or accept it.

Perhaps we are now so conditioned to seeing violence and its aftermath – not inured to it, exactly, but perpetually braced for the next awful event – that vanilla dramas leave us cold.

If so, then the dismay and revulsion of people like me could be a sign of incurable wimpishness, a stage of life where, come evening, it’s wisest to settle down with crochet and listen to the wireless. Or possibly it’s what I’ve long suspected: people watch TV with half an eye, while scrolling through social media, doing the ironing, or delousing the dog.

How to make them drop everything and watch? By scaring them, and all the rest of us, witless.