The Scot was a controversial appointment back in November, following revelations of offensive text messages sent between himself and then Cardiff City head of recruitment Iain Moody during the pair's time in south Wales.
Mackay was sacked on Monday, after winning just five of his 24 league matches in charge, with none of those victories earned in front of Wigan's home fans.
Wigan sit 23rd in the Championship, eight points from safety with only five matches remaining and replacement boss Gary Caldwell facing a tough ask to keep them up.
"My reaction was less shock, more a pleasant surprise," Alan Moore from Wigan fan website 'This Northern Soul' told Perform.
"Mackay should never have been appointed manager of our club.
"He was a bad fit in terms of reputation and style, and things have gone from bad to indescribable during his time with the club.
"The chairman stuck his neck out with this appointment and the utter mess that followed lead to him being stubborn about the manager's continued employment despite results and performances showing no sign of improvement over the last five months.
"The only shock is that happened with so little of the season left and such a little chance of survival remaining. If a change in manager had happened a couple of games ago then there would have been a reasonable chance of turning things."
On the appointment of former captain Caldwell as manager, Moore said: "He wouldn't have been my first choice, but despite his reputation as 'Captain Calamity' this could turn out to be a genius appointment.
"There's little to no chance of him affecting the outcome of this season but making the change now means that we can put it all behind us and get on with trying to enjoy our football again.
"Beyond that? He's got two rebuilding jobs to do, firstly with what will be left of his first team squad and secondly with the foundations that we started to lay during our last few years in the Premier League.
"Caldwell may already be booked on some coaching courses this summer; he might be better off booking on a bricklaying one instead."
