shopping Store-bought peppers

Same for tomato.  I think it is a couple of reasons.  First the grow methods.  Goal being get it in the ground and then off the plant as fast as possible.  Completely different goals, so different methods.  Then there is the big one: DNA  The variety of produce usually available in the grocery store was bred to be in the grocery store more than anything else.  Huge considerations other than production volume and speed are things like how long will they keep reasonably fresh on a produce truck and in the stores.  Also, things like ripening at the same time.  Oh and appearance to the consumer.
When you grow your own, chances are things go from plant to mouth fairly fast.  My favorite tomato is mortgage lifter.  The flavor is amazing.  Thing is, they are ugly and dont keep very well.  So they will likely never be seen in a grocery store.
The variety of produce usually available in the grocery store was bred to be in the grocery store more than anything else.
Just look at the jalapenos in most stores. There are nearly all large hybrids with a big emphasis on size. They bred out all the traits that make a jalapeno great. There are some really decent pepper hybrids such as Early. I would imagine at one time those were bred for markets too. Some of them are bred just so you cant reproduce the same product from saved seeds such as Biker Billy. Sometimes its just as minor as removing corking. Some people seem to think it looks like an imperfection and hurts sales.
I wont even touch a off season tomato at the big grocery stores. They just plain suck. Growers ship them suckers out green and they artificially ripen in transport.
Yeah, try to grow a Biker Billy from saved seeds and there is no telling what you will get. To be fare though i dont think it was ever intended to be a market variety. I dont even know for sure if my Fresno will grow true or close to true. The pods from the market were great just pricey so i had to try.
I feel lucky because Fresnos around me are pretty cheap, usually one extra dollar per pound over Jalapeños.

A lot of the varieties that are pointless to save seeds from are just f1 crosses, like Savinas and Hot Rod Serranos. That first generation that you bought seeds for, it's going to be stable but if you save seeds, you'll have that whole f2 situation where weird recessives pop out and you won't be able to count on uniformity at all. I think it sucks but I grew Hot Rods 2 years in a row because they're damn good Chiles and the plants are turbo productive. But this year, I'm growing them alongside two other varieties of Serranos because, frankly, I'd rather work with stable and classic strains. That's just my personal preference, and it might not even be strong enough to keep me from growing HotRods again anyway.

I'm growing four different types of Jalapeños this year, too. I want to pick a favorite for those as well. I'm growing the NuMex Vaquero, which are supposed to be pretty hot and disease resistant... But they are a hybrid of some sort and even the plants just look weird. The leaves and all... So, the pods are going to have to be REALLY good for me to grow them again in 2019. I'm most psyched for the Zapotecs, which are apparently a landrace Jalapeño from Mexico, no matter what Willard says about the subject lol...
Fresno here are pushing $5/lb and only one place carries them on a regular basis. I can get jalapenos for under $1/lb on sale and always $1.50/lb or less. Problem is i want them ripe and that never happens even at the markets in "little Mexico". Serrano are not too expensive and easy to get but almost never ripe. I tend to grow what i cant get at an affordable price or cant get at all locally.
You would think with the number of Asian markets near me and some of them are huge i could get fresh Chinese peppers....NOPE!!! Had to grow Sichuan peppers this year just to be able to try them fresh. I can walk into any Korean owned market and get fresh gochu including ripe when in season. WTF!!!! Same with Thai and Indian peppers....i can get them no problem and some of them are cheap too.
I'm almost convinced that these habaneros are crossed with a ghost. I just cut another open and had deja vu relating back to when AJ Drew sent me a box of ghost peppers. The smell is almost identical. The only difference is that the peppers from him had such a great taste that I ended up snacking on them (my tolerance is barely above habanero level). These just taste like heat.

Edit: had a little piece of one and it had a little bit of that same kind of sweetness as those ghosts. Though, it also had a kind of weird, chemical-y taste as well. Definitely similar though. They look exactly like a normal orange hab though so maybe it's in my head.