It might make it easier to prove there is malicious intent. If I'm in a completely separate business and I make a remark about your business practices, one can

It might make it easier to prove there is malicious intent. If I'm in a completely separate business and I make a remark about your business practices, one can see it as an outsider making a (negative) observation if the language is only mildly disparaging. If I'm in the same business as you, it might come off as more of an attempt at me undermining you or trying to gain some benefit. Ultimately it probably doesn't make much difference, in that defamation is usually difficult to prove anyway, but the context could sway things a bit.