Yes, systems built with if/else rules are intelligent, in that they reproduce some heuristic rule that someone had to think about. I think the term "expert system" is kind of appropriate for them
https://en.wikipedia.org/wiki/Expert_system
Of course they are not too intelligent, but, they are more intelligent than a rock, say. (unless this rock happen to be a chip running some neural network)
Though when we talk about AI now, we are talking about what the _public_ thinks "intelligence" means. This really muddies the conversation, because these technical distinctions we are making now fall completely flat. I think when you tell random people that we have created "artificial intelligence", they think we mean what I am referring to above as "creative intelligence", not "it executes an if/else rule" intelligent. So as AI becomes a topic in the mainstream, our conversations are likely to be completely misunderstood because of the colloquial meaning of the technical terms we use.