This is a 100% yes. Is Ghostbusters perfect? No. Is it great on its own merits? Absolutely. As many have said before me, the performances and effects more than make up for any other shortcomings the script may have. But we're not debating whether or not this is the most perfect movie. We're debating whether or not it is a canonically important film, which is absolutely is.
Ghostbusters quickly entered the mainstream and it never left. This is a model that has been copied often, and never successfully. But movies are often compared to this. Christ, when they decided to remake it they practically broke the internet. People are Passionate (with a capital P) about Ghostbusters. Even people who haven't seen any iterations of Ghostbusters will immediately be able to picture some of the more iconic characters.
I love Ghostbusters. It's a fun, fun movie. I would put it in the Canon just for that. But the impact it's had on popular culture can not be ignored.