"Teejay", I think the use of 'crap model' in this context refers to kits that aren't up to the current standard of very precise tooling you see in the latest releases from (most) modern manufacturers. Though, technically, being a recent tooling does not preclude a kit being 'challenging' to construct to a high modeling standard. In short, 'crap' is something used by experienced modelers!
To me, a 'crap' kit is one that requires a whole lot of correction for accuracy's sake. I can almost always deal with molding and fit issues successfully, but having to cut out and correct large portions of a model simply to make it 'right' is (in this day of internet-based research resources & large online modeling communities) just unforgivable. So, just because it is "new" doesn't necessarily make it better. To provide an example (which I must unfortunately 'name names'), the new tool 1/48 scale P-80C kit from HobbyBoss, which is a wonderful example of the mold-maker's art yet is still an inaccurate representation of the aircraft. A more accurate (and consequently to me, better value for the money) is the quite old Monogram (NE Revell) P-80 kit which features more accurate shapes, dimensions and panel lines (although they are raised panel lines...not quite the 'sin' it seems to be these days.) Essentially, HB failed on basic research - an apparently common issue with many Chinese kit makers. I suspect the high reliance on computer-based design work, relying almost exclusively on images (often web-sourced) is the cause of these problems. Without proper basic research, images alone will easily lead a CAD designer astray (as proven time and again.) If the draftsman (as we'll call these techs...) has never even *seen* an aircraft, it must make it hard to interpret and just 'understand' the structures they are attempting to 'reverse engineer' in their 3D drawing spaces.
So, back to your original question. I feel that the label of 'crappy kit' will be different for every modeler because everyone has their own modeling 'profile' that develops from their own experiences, skill-set and expectations. While some will expect the 'shake & bake' kit every time and be disappointed otherwise, others will see the potential in a kit. Everyone has their own unique set of 'rose colored glasses' when it comes to kits. My friend Dennis often says '"Life is too short for crappy kits"' because he is 'destination oriented' (that being a finished model.) I am more someone who appreciates the 'journey' and so-called 'crappy kits' can provide quite a modeling journey. To me, the hours that simply fly by while I am in 'the zone' at the workbench is where my fun happens. Once they are finished, however, I'll probably not spend hours looking at them!
Philosophy aside, however, there are definitely kits to avoid when getting back into modeling (or doing it for the first time) just because of the frustration potential. Adult modelers in particular will observe the results being had by others and unfortunately develop expectations of similar results for their own modeling. The key concept is 'experience.' Someone who has been practicing the craft for many years will have better results than anyone who is just starting out. Some of this can be 'shortcut' by reading up and going to local club meetings to learn, but regardless, it still takes practice (like anything.) With that in mind, I would recommend getting some of the so-called 'crap kits' and using them for just that practice of the basic skills required to turn out well built plastic models (if indeed that is your desire - modeling should, at it's core, be low stress and fun, so don't 'self-induce' problems...focus on the journey, as it were, and you can't go wrong.) Calvin & Hobbies comic strip illustrates the basic quandary of the new modeler:
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So (not knowing your interests) I'd say Lindberg & Glencoe produce kits that offer, while of older tech (and consequently typically suffer from poor fit and have molding quality issues) low parts count, some unique subjects and plus, they are cheap. The Pegasus Hobbies range of kits are excellent modern toolings, being good value for the money and of some unique subjects. Moebius Models' kits are also good for the same reason, though some of their kits (like the 'Batman Begins' Batmobile vehicle) are very complex. HobbyBoss has a range of 1/72 scale aircraft that offer low parts counts and quick construction, though as noted, may also have accuracy issues. And so it goes...
Regards, Robert