The original poster uses the word “better” three times…which do you view as weird?
His first use is where he says he wants something “a bit better than QbA”.
The different ripeness categories are referred to as “quality levels”, which gives the impression that each level is somehow a better quality than the one before. We know that this isn’t necessarily the case and that the levels, at least above QbA, refer to ripeness of the grapes. HOWEVER, in most cases it IS the case that QmP wines are of better quality than QbA (in addition to being riper).
The fact is that the QbA designation means, (i) grapes are allowed from a much broader (less strict) set of growing regions, (ii) ripeness levels are so low that chaptalization is allowed and is often needed for the wine to reach the minimum alcohol content required, and (iii) the wines are less expensive (and have greater production volumes) that the QmP wines of the same producer, generally lead many people to understand that QbA is, in essence, a lower-quality wine as compared to the predikat wines.
Producers use more rigorous grape selection standards (beyond the geographic and legal ripeness standards) for their QmP wines Even Wikipedia, in its explanation of the quality designations, refers to QmP wines as “superior quality wines” and while it notes that as between the different QmP levels (kabinett, spatlese, auslese, etc.), “the term ‘quality levels’ is a misnomer, as ripeness is not necessarily a predictor of quality” it then goes on to state that QbA wines are “basic, everyday, inexpensive quaffing wines” and that “exciting things are rarely made.”
So it doesn’t seem “weird” to me at all to make the generalization that a kabinett is usually “better” than the QbA of the same producer.
His second use of “better” is in the context of wanting something “better than” the suspiciously inexpensive wines he sees at his local store.
It seems reasonable to assume that, as a broad generalization, more expensive wines are likely to be “better”, and that wines at a certain price point (e.g. $10-$15) are not likely to be exciting. As David’s post just before mine points out, as a whole, German Riesling can be very reasonably priced, and relative to other wine regions, very good Riesling, especially at the Kabinett level, doesn’t have to be expensive. However, I too would be “suspicious” of buying inexpensive Kabinett at very low prices (e.g. under $13) of an unknown producer.
His last use of “better” is in reference to seeking a wine “better” than Muller. At that point, I would probably quibble with the term better, though it’s quite clear that he’s asking for recommendations of a producer whose wines he might enjoy more than those of Muller.