As others are pointing out, this is a poor argument and should not be modded up.
Build a dedicated line, from everybodies house to their work
That's a strawman argument. I simply suggested if we could commit to the cost, extending public transit options further into the suburbs is a nice thing to have. Whether this means more buses, or extending a metrorail further out like they have (successfully) in Virginia. It could also mean having more options between cities.
You understand the underlying economics?
No need to condescend. Other countries manage to have more frequent, reliable, and accessible public transit options (rail and bus) than we do, and they seem to make it work. I'm sure our brightest minds could figure out a way to do it. At the very least it is worth a try.
The Wright Bothers weren't the first to fly. They were just the first not to crash.