There had been a backlash from a section of the support when it emerged Arsenal were signing the former Chelsea winger.
But Arteta, ahead of today's clash with Nottingham Forest, said: "I can talk about what I've seen and what I have experienced and I think the welcoming that our supporters gave to Noni from day one it was incredible. So, I don't know all the ways that people communicated the disagreement with that.
"But our supporters, they've been exceptional and rightly so, because he's an unbelievable player."
On competition between Madueke and Bukayo Saka, Arteta also stated: "When that day comes, that B (Saka) is in his best condition and Noni the same, that's what we want, and I'm very happy to have him.
"I think, looking back at what he's done with the national team as well, I’ve spoken with Thomas (Tuchel) as well, I am very pleased with that. He's really good and he's in a really, really good moment."