It wouldn't be a trap if the games weren't good. Think of it like fishing, bad bait doesn't catch anything. When people use words like 'trap,' and even when I talk about it in terms of 'religion' or 'indoctrination,' I'm not saying the games themselves are bad. Nor am I automagically contributing malice to those that call it a 'trap'. The games have to be good for those descriptors to fit.
The question posed is,
why do you think Nintendo is so successful? Those kinds of descriptors, whether used in malice or, in my case, more tongue-in-cheek, make sense IMHO when you look at customer retention. It's not even unique to Nintendo. It's a universal feature of most industries. For example a household where the parents had elevated F50's are highly likely going to produce children driving around with elevated F150's or just pickup trucks in general. This kind of brand loyalty happens naturally, and I'm sure Nintendo is fully aware of it. But the trucks themselves still have to be solid, if they were constantly breaking down or disappointing, parents would move on to something else and kids would grow up with a different experience entirely.
What I see here is that some people have let their love for Nintendo morph into resentment for how Nintendo manages their ecosystem, how they gatekeep, how they leverage nostalgia, and how they're unapologetic about their business model. That doesn't mean the product isn't great; it just means the way they keep you hooked can feel manipulative, even if you're willingly eating the bait like I happily do
every single god damn time hook line and sinker. 
Some of y'all just seem mad that I'm not scared of you enough to keep my opinion to myself.
