a) Plants need to be carefully picked for their habitat/location/which room in the house etc
b) Plants need varying amounts of care
c) 1 a month quickly scales to unwieldy numbers if you are able to keep your plants alive, unless this is aimed at the disposable "fast fashion" part of plants?
That being said, indoor plants are the best. I can't help but feel like this is the equivalent of those fake/plastic plants though.
I've recently come to believe that most people are really bad at taking care of plants.
Those cute little tropical things at the garden center? If well-cared-for, they will grow into 8-foot-tall (a little over 2 meters) monsters that live for decades. There's no way there's a big market for 8-foot jungle plants. Even those tiny little Haworthias and Echeverias will start to outgrow their cute little nursery pots within a few months.
People must be keeping them in small pots, over/under-watering them, and never re-fertilizing the soil.
Case in point, when I broke up with an ex and she moved out, she took the Cycas because it was "hers". It had just started sprouting a new set of fronds. Those things are really easy to take care of -- just give it some water like every 2 weeks, give it light, don't let the cats chew on it. Within 3 weeks she had somehow managed to hurt the thing to the point where the new fronds had gone totally brown and soon withered away completely. My guess is she thought it looked dry and overwatered it. I eventually took it back and it's made a full recovery since then.
(I totally agree though, I suspect many of these plants will die in short order)
I think the only sustainable market is first-year college students. Small, drought-resistant, shade-tolerant plants for shelves and windowsills in a dormitory. Constant rotation of new people moving in every year. Could be a nice stable market.