This is slander! I am not an ex-art student! :)
I would agree that "it's not my bag" is a fine thing to say about some art gallery piece that fails to inspire you, but when a statue is foisted upon the public square, with possible state cooperation, we're allowed to criticize it. He has inserted it into the conversation.
Moreover, the main complaint about this statue isn't coming from some expert artiste perspective, saying that it's somehow unsophisticated as art. The complaint here is that it's making a truly banal political statement. The entire piece consists of making that statement, with little else to recommend it. (Indeed, most political art is hack, unless it's saying something really original or really well, and it's even worse when it tries to be cute about it.)
So here, the complaints are coming from everyday onlookers who might not be qualified artistically, but who are able to say which sorts of statements are tiresome and overplayed in the culture we all live in. We are all qualified to ask ourselves whether this predictable statement advances or degrades the conversation.
Anyhow, FWIW, I just looked up Simon Berger's portraits based on your comment, and I really like them. Thanks.