You can still get "box of basic Legos"; I believe it may even be possible to get "big ol' bucket of Legos in a specific color". I am pretty sure that it is still quite possible also to get non-licensed set-types, like "pirate crap" and "knights crap" and "automotive crap".
However, except for tiny pocket-sized sets maybe, these are not what you will find at Generi-Mart's toy section, because they are simply less profitable than the Harry Potter Elf Hutch or Star Wars Dagobah Latrine set. A market environment where the toy store is replaced by a small toy section in your local Conglomo means that you will tend to have a narrowing of selection both to facilitate cost-saving bulk purchase and make the most of valuable floor space. The items that survive the narrowing are two groups: those with high and obvious profit potential (that is, licenses) and cheapo throwaways/knockoffs of aforementioned licenses. (The cheapos also sometimes get squeezed out of Huge-Mart and must be sought at drugstores and supermarkets.)
The net outcome of this is that you will need to either shop online or find an actual toy store to get basic Legos. I would encourage anyone who wants to buy toys to go to an actual toy store anyway, but they seem to be depressingly dying out.
As far as the "Legos targeted at creepy collectors" goes, that's actually not quite true in the sense you might think; Lego collectors do buy the odd licensed sets, but generally not (to my limited knowledge) for the purposes of building the indicated object. Rather, they do it to get the potentially useful unique blocks in that set. I'm told that, for example, the Hogwarts Castle set has some very useful pieces for a Lego builder who wants to make Gothic cathedrals.