I think some people do not understand the legal definition of a monopoly. A monopoly is any business that dominates the heck out of its industry. There's no question Google is a monopoly.
That said, a monopoly is not automatically illegal. AT&T enjoyed one for decades, until lawmakers decided their lack of competition was hurting consumers.
So, yes, Google is a monopoly, but if some people are fighting that point because they think monopolies are automatically bad/illegal and that's what's being said about Google here, that's just not the case. They're fine as long as they're serving the marketplace well enough that lawmakers don't feel the need to interfere.