You don't seem to respond to those things.
If you ask a skilled professional to do menial trivia, expect to pay for their skill level.
Yeah an inner tube for $35? And it's not even those fancy orange ones?
Well it's not hard to change it yourself, as long as they're not charging more than $4 for a basic ones. If they are actually selling it for $35 that's pretty yikes. I'd just buy it online given that it doesn't benefit from retail (you don't need to see a tube in person, just need to know the dimensions)
Bike shops need to charge for labor because most people don't buy bikes from bike shops anymore, so labor is where they make their money. $100/hr for labor is on the higher end but doesn't seem crazy in expensive locations. Not to mention that the prevailing way people treat bike shops (as places you can walk in at any time, get your bike fixed, and walk out) is incredibly antithetical to bike mechanics actually being able to take the uninterrupted time to focus and do good work.
Is it actually noticeable for an average cyclist? I don't doubt it, but I wouldn't be surprised if it was a marketing slogan from carbon frame producers and people went with it, and since their bicycles were more expensive, they "felt" better.
There are commuter bikes for $100 but it's just not worth servicing them because telling someone it'll be 40% of the original bike price in labor + parts to fix something not major is hard for them to accept.
> low maintenance, comfort, and ruggedness. Apparently that's totally uncool and biking is all about ultralight and ultrahard--feel every crack in the pavement through the hard plastic saddle!
Carbon is more comfortable by reducing the vibrations that you'll feel compared to aluminum.
The reason why they stock shitty parts is because they appear to service really cheap bikes and for people who buy cheap bikes, that's what they want. I know many shops who wouldn't service cheap bikes and I know many shops where they would but I wouldn't trust them with my more expensive Trek road bike. So it's strange that they also stock carbon frames.