He told Express.co.uk: "I think it was insensitive. I was always trying to be fair to them.
"When they made their initial statements about their change in life plans and they had said how they wanted to become "financially independent" – that was their objective – and I think that's a very noble objective.
"And I had hoped that they would clarify that meant they did not expect taxpayers, certainly in Canada, to be paying for them.
"They had plenty of opportunities to do it, they were given plenty of opportunities – I am a bit mystified as to why they didn't clarify that very early on."
The tax campaigner went on to claim that the ill feeling generated by the episode had undermined support for the monarchy in general.
He added: "Harry and Meghan's saga has not helped. It has definitely made a lot of people question whether or not our institutions need updating."
The Queen is officially Canada's head of state and according to the constitution her assent is needed to enact all legislation.
Over the years, support for the monarchy has decreased, partly as a result of changing demographics, resulting in fewer and fewer people having a heritage and cultural link to the royal institution.
According to a Yougov poll carried out in January, more than two in five Canadians want to cut ties with the Queen.
The YouGov survey data shows 44 percent of Canadians strongly or somewhat support abolishing the monarchy in Canada, while 29 percent strongly or somewhat oppose the notion.
Canadians aged 35-44 are more likely than any other age group to support the idea.
Mr Wudrick argued that the scandal surrounding expenses for Governor Generals has also seriously damaged the reputation and legitimacy of royal institutions among the public.
The Governor General is the Queen's representative in Canada, carrying out various administrative and ceremonial roles, such as signing into law legislation passed by the Canadian parliament.
The Canadian government appoints the Governor General, who normally serves a five to seven year term.
The position comes with many perks, such as a generous pension and a grant worth millions of dollars to help fund a Governor General's charitable activities, once they have stepped down from their role.
In addition, retired Governor Generals are entitled to continue claiming expenses from the government for an indefinite period of time, which is all funded through taxes paid by the public.
Mr Wudrick explained: "Governor Generals are allowed to bill expenses – an unlimited amount to taxpayers.
"They are not required to provide any details and they're allowed to file these expenses for ever. So we have one particular Governor General – her name is Adrienne Clarkson.
"She ‘s now been retired for almost 15 years – she has billed more than a million dollars of expenses in that time with no transparency and it is an unbelievable policy and no one can understand why this policy exists."
He added: "It blew up about a year ago and it kind of went away but because of what has happened with Harry and Meghan – the issue of spending money on royals who are not doing anything – this has become a much more topical thing again."
And Aaron Wudrick, federal director of the Canadian Taxpayers Federation, also claimed that the behaviour and silence of the Duke and Duchess of Sussex throughout the saga had helped to undermine the legitimacy of the monarchy in a country already divided over its support for the royal institution. The royal couple officially stepped down as senior members of the British Royal Family on Tuesday and have already embarked on a fresh start in Meghan's native Los Angeles. Before moving to the US, Meghan and Harry had been living in Canada since November, which sparked a row over who should be paying for their security costs.
Mr Wudrick was the man behind the petition that called on Justin Trudeau to ensure that "not a penny" of taxpayers' money would go on subsidising the security costs of Harry and Meghan, which are believed to run into millions of pounds.
The petition soon gathered over 100,000 signatures from Canadians, outraged that ordinary hardworking people were seemingly expected to pay for the protection officers of the multimillionaire royals.
Eventually, at the end of February, Canada's Public Safety minister Bill Blair announced that the government would cease paying the security costs "in the coming weeks".
Mr Wudrick believes that Meghan and Harry could have easily defused the toxic row, by making a simple statement to the effect that they did not want or expect ordinary Canadians to pay for them.