Wenger has come under a barrage of criticism and has portrayed a forlorn figure at times this season, with his side unable to cope with a crippling injury crisis and now facing an uphill battle in their quest to regain Champions League football.
A FA Cup semi-final win over Wigan Athletic, albeit via a penalty shootout, was enough to lift the spirits of some of the doom-mongers, as the Gunners booked a place in the Wembley showpiece next month. But many of the Gunners fan-base believe a change is needed to taste the good times once more.
Arsenal have suffered some embarrassing defeats to their closest title rivals, and the thought of missing out on a place in Europe's elite club competition does not bear thinking about given Wenger's proud record of qualifying for the Champions League 17 times on the spin.
While the club's nine-year wait for silverware could come to an end if they see off Hull City in the cup final, Demel - who joined the Gunners in 2000 but never played for the club - believes the condemnation of Wenger is unjust and fails to take into account just what the 64-year-old has achieved for Arsenal.
Talking to the official West Ham website, Demel said: "There is a lot of criticism of [Arsene] Wenger because they haven't won a title for eight years, but they forget how he changed English football.
"How the players trained, the fitness and the structure at the training ground. He has really brought something to English football and a lot to Arsenal, so I hope people can realise that for him. From my point of view he's a good manager."
Demel also discussed at length his short spell with the Gunners, which ultimately yielded no first-team outings. But the 32-year-old insists he learned a lot under Wenger's tutelage as he gears up for a return to his former club in a crucial clash for the Frenchman and his side this evening at the Emirates Stadium.
"It was a great time when I went to Arsenal," he added. "I was young and I learned a lot. It was my first experience [away from France] and it wasn't easy for me, but I had the chance to train with players like Vieira, Henry, Adams, Keown, Parlour, Pires.
"It was important for my career to be at Arsenal at that time."