As I read Colville, he would say "do not take part in that type of thread but post away on the pineapple one, because then the community will like you". Which makes sense if you are trying to sell something.
		
		
	 
I think the difference is that the pineapple thread is obviously offtopic.
He focuses on communities built around a specific thing (in most cases a product). If we take his own product as example, lots of people get excited for 
Draw Steel. They get together and they start talking about it. They're positive about the product, but the discussion might be about things they like, things they don't like, what's the best way to play it, what should be avoided. That's all valid discourse. Some might even come and say "I like the game but really dislike how it manages X".
The problem is when you have actors that come in this space for people excited about something, and that they're not excited about that something, and they just want to falsely criticize the product or convince others that they're wrong about it. It's definitely not a majority. The one I see the most (on Reddit specifically) is someone asking a question about 5E. Let's say 
"I'd like my 5E campaign to be a bit grittier, even though we don't have that many encounters but each encounter is a big deal". Appropriate answers would be discussing why 5E's design is not oriented towards that, what parts of the design are in the way, ways you could go around that. Carefully worded suggestions about alternatives to 5E could even be appropriate. 
But I really often see a blunt 
"5E is just a poorly designed game. It does nothing particularly well. Do yourself a favor and play something else". That right there is not a discussion, it's not a criticism (saying something is bad or imperfect is 
not criticism) and it doesn't invite neither.