These are marketed mainly towards children, with buzzwords like "easy," "low-maintenance," "ideal gift," and "decorative." Companies rely on the fact that the general public is unaware of the actual care involved in keeping live animals, and get away with selling overpriced Tupperware containers labeled for "bettas."
Other then typically being overpriced, these containers are highly unethical and boast misinformation on their packaging. Aqueon's "Betta Castle" boldly states "wild bettas are brown." A quick google search disproves this. Though some can be brown, this is true of betta splendens as well.
This is not a problem with a particular brand, either. The entire industry is at fault. It's up to the consumer to educate themselves and ultimately demand better for these fish.
Please visit Can my betta live in a bowl? to learn more.
These are another type of kit that has turned into a trend over the past few decades. You buy a vase, stick a plant on top, and put a fish on the bottom. Some people seem to think the fish survives by nibbling on the roots of the plant. This is false. Bettas are insectivores and need a diet high in protein, something plants do not provide. Often these containers are just as small as betta kits and even less informative of how to care for a fish. One packaging states that the plants keep the water clean, so you don't have to do water changes. This is terribly inaccurate.
You certainly can keep plants and fish together, and plants do help keep the water clean, but this can be achieved by using appropriately sized tanks, with filters and heaters. Avoid these "aquaponic kits."