The Shareholders' Association says Skellerup's investors have lost out because the company lacked a cohesive succession plan for its board.
The stock market's disciplinary tribunal on Monday fined Skellerup $25,000 for not having at least two independent directors for almost a year, viewing the breach as very serious.
Shareholders' Association chairman John Hawkins says independent directors are critical to representing the interests of non-controlling shareholders, particularly smaller investors.
Mr Hawkins says it's very concerning that important safeguards put in place to protect investors had been ignored for such a long time.
He doubts the shortage of independent directors affected the way the company was run in this case, but says shareholders have still lost out because the fine comes off the company's bottom line and is a waste of money in tough times.