Bedrockgames
I post in the voice of Christopher Walken
Ultimately, I do think that such choices are a matter of taste and preference. Some people will never like ribs, for example, even if they're at the best rib joint in the world. But, setting aside taste and preference, there's something to be said about the advice or insight that can be offered by someone who eats the same thing every time, and someone who's tried more than one thing.
Also, while this is a very imperfect metaphor, just to come back to it for another point: I think both these people actually have something to offer. The guy who gets the steak every time, is going to be able to tell me how consistent that steak is. The guy who gets something new every time, is going to have a wider variety of options to talk about, but any one of those could have been eaten on a good or bad day. In gaming terms, a person who plays one, or a handful of similar games, is going to have deep knowledge of those systems. A person who plays lots of different games all the time, is going to have less deep knowledge of the individual games I think. Of course, most people are not this stark. I imagine most gamers will be closer to the center of the spectrum.
The examples in the metaphor are really a bit extreme I think. In reality, you'd more likely be dealing with a) Person who has a handful of regular items they routinely order on the menu because they consider them reliable, and b) person who different things more often.
Also I don't think anyone here is seriously advocating not trying different food. This conversation is more like, some people in the room don't like seafood, and so suggesting they try the calamari probably isn't going to go over well (for the record, I like calamari a lot).