The founder of BrewDog, James Watt, met with short shrift from small investors who have been left empty-handed by the company’s sale for just £33m, after he admitted to “many mistakes”.

Watt issued a mea culpa via the professional social networking site LinkedIn, a platform he has regularly used to espouse political views, including complaints about the level of tax that the multimillionaire and self-styled “punk” is asked to pay.

He apologised to more than 200,000 “equity punks”, who invested £75m in the business through multiple crowdfunding rounds but received nothing from the sale of the business to US cannabis and drinks company Tilray Brands.

They lost out partly due to the terms of an earlier 22% investment by private equity group TSG, which involved Watt and his co-founder Martin Dickie cashing out to the tune of £100m but left crowdfunding investors with little chance of a return.

Watt also declared himself “heartbroken” for the 484 staff who lost their jobs in the deal, after Tilray opted to buy only 11 of BrewDog’s bars, leaving 38 to close their doors.

“During my 17 years in charge there were highs, lows, successes, failures, huge gambles and many mistakes along the way,” said Watt.

“Ultimately, the mistakes hurt far more than the successes console,” he added. “I would have loved to save every single job and every single equity punk investment. Ultimately, I couldn’t. That will stay with me.”

Unite, the trade union, has already criticised the “national disgrace” of the sale, conducted via a pre-pack administration that involved administrators Alix Partners agreeing a sale to Tilray before declaring insolvency, at a cost of nearly 500 jobs.

On Wednesday, LinkedIn user Fraser Campbell said Watt had “walked away with £50m from the TSG deal, while everyone who gave you their money is now left with nothing but the taste of sour beer in their mouths”.

John Allison wrote: “Are you ‘heartbroken’ you gave the institutional investor preference over the equity punks James?”

Another LinkedIn user, Cathal Morrow, questioned Watt’s description of himself, in his LinkedIn profile, as a “punk”.

“Genuine comment – do you think it’s still appropriate to have the word “punk” in your bio,” he said. “Rather insulting at this point I’d say”

Others were kinder.

“As one of the early Equity Punks, I never bought shares expecting to get rich,” said Fraser Reid.

“I bought them because I loved the beer, the attitude, and what BrewDog represented at the time. Building something from a garage to a global brand is no small feat.”

The £33m sale, a fraction of the £2bn value that BrewDog once targeted when it hoped to float on the stock market, comes less than a month after the firm put itself up for sale.

BrewDog’s decline from its all-conquering peak was cemented by five years of losses and a string of brand-damaging controversies relating to the company’s culture and treatment of staff, particularly under Watt’s tenure. Watt later apologised for what some staff described as a “culture of fear”.

Watt also hired private investigators to look into people who took part in a BBC documentary about the allegations.