They're feeling the heat in the Gourmet Burger Kitchen (GBK) with that poorly conceived anti-vegetarian advertising campaign which has come under intense fire – and it shouldn't have taken a genius to see it coming. Somehow, GBK's marketing folks managed to miss the biggest marketing trend of all.

Recent research shows 12% of UK adults and 20% of 16 to 24s now follow a vegetarian or vegan diet. A YouGov survey from 2013 revealed that a quarter of the UK public ate less meat than the year before and that concern for animal welfare was the main reason why.

Vegetarians and vegans have reacted to the GBK ads, which targeted 'grass' eaters. People responded with tweets such as "You have also reinforced the stigma behind vegan diets, poked fun at animal suffering and p****d your customers off", "Distasteful, disgraceful PR.. Great way to lose customers!" and "#vegetarianism is not a trend that you give up for a crappy burger".

In a series of tweets, GBK later apologised for the campaign: "Our intentions were light-hearted and not meant to cause any offence, but clearly we have, and for that we apologise".

It's not hard to see why people took to social media in this way, when they choose not to eat meat due to the suffering of the millions of cows, pigs, chickens and other animals killed for food each year. Every one of them is an individual with feelings and personalities, yet they can be mutilated, dosed with drugs and crammed by the thousands into filthy, windowless sheds – all for our consumption.

Most people have seen investigations that have exposed abuse of animals on farms in the UK, but many are also coming to see that the treatment of animals in the dairy and egg industries is as bad or worse. Cows, like other mammals, produce milk only after they give birth. They are strapped to what is often referred to as a "rape rack" and are repeatedly impregnated. The industry tears their calves from them after only a few hours. The natural life span of a cow is 20 to 25 years, yet nearly all cows used by the dairy industry are slaughtered for meat – typically, at around 6 years old.

It's no wonder that many vegetarians are going vegan, and many vegans describe their decision as the best choice they've ever made. So, in fact, GBK was right to say in one of its ads that "[y]ou'll always remember when you gave up being vegetarian".

Animal suffering isn't the only reason to swap beef for a beetroot patty, people are becoming more aware of the adverse environmental impact of animal agriculture. The impact of beef per calorie on the environment is extreme – when compared to staples like potatoes, wheat, and rice, it requires 160 times more land and produces 11 times more greenhouse gases. The UN has stated that a global shift to a vegan diet is essential to combat the worst effects of climate change.

A growing number of celebrities are making the connection, too. Over the weekend, vegan boxer David Haye demolished his opponent, Mark de Mori, in a little over two minutes. Haye gave up consuming animal produce after seeing the abuse it involved and realising that he "couldn't be a part of it any more". He joins celebrated athletes such as Venus and Serena Williams, Carl Lewis and even Mr Universe, Barny Du Plessis, in eschewing animal products.

All around the country, vegetarian and vegan food outlets are springing up, and others are offering more vegan options. Thousands of people have signed Peta's 30-day vegan pledge this year already, Veganuary has around 22,000 people taking part in 2016, and Handmade Burger Co is offering 50% off its vegan burgers during the month of January. Indeed, just last year, GQ magazine declared the Superiority Burger from New York City to be the best burger in the world – and it's 100% vegan.

Oprah Winfrey once said that the start of a new year offers "another chance for us to get it right". One way that GBK could get it right would be to increase its vegan-friendly options and target the rising numbers of vegans, vegetarians and "meat reducers" in the right way, instead of alienating us, and dismissing our ethical choices. It can't be great for GBK's bottom line when #gourmetmurderkitchen is trending.

Mimi Bekhechi is Peta UK's director.