>"Bikes are expensive personal transportation, compared to not owning any"

I will admit that my bike cost $550, but it's also a really nice bike. You can get a perfectly serviceable, reliable and comfortable bike for less than half that. And it'll last for years and years with minimal maintenance (or none at all, even).

Yes, obviously owning something is more expensive than not owning something. But if you walk everywhere, you also have to account for time spent going 5kph instead of 20kph, not to mention shoes that wear out quicker. I used to commute 3km by foot, and my shoes wore out very quickly, even good quality sneakers didn't last long.

Not to mention payment for using public transit or taxi services or car rentals.

>"they take up space in every home with muddy, oily mechanisms"

I park my bike outside, locked to a bike rack. I ride in the city, it has never been muddy. I do a lot more maintenance than the average cyclist, I wipe down the chain if I've been riding in the rain, and I actually lube the chain and other mechanisms once in a while. Most people don't do anything at all, and their bikes still give them years of service. On my bike the chain is exposed, I prefer it like that for ease of maintenance. Most commuter bikes have enclosed chains, some have belt drives.

>"they take up a lot of space in bicycle parks outside every desirable destination serving to push everything further apart for humans on foot"

They do take up some space, but dramatically less than most other forms of transport. Based on my experience here in Copenhagen, it really isn't an issue. Bikes left abandoned on sidewalks and in bike racks are regularly marked and then taken away, especially if they're obviously broken. There is plenty of space for pedestrians here.

>"they don't mesh well with pedestrians (in a collision with a pedestrian and a fast moving metal bike, the pedestrian loses)"

That is why we have sidewalks, bike paths and streets for motorized traffic, grade separated from each other. On shared traffic streets, cyclists slow way down and everything flows nicely. Only idiots would race their bikes down a street like that, it happens extremely rarely. Pedestrian/cyclist collisions do happen, but they're usually very low-speed affairs, unless a pedestrian steps out in front of a bike on a bike path, without looking. Certainly not the cyclist's fault.

>"they require equipment you might need to carry (locks, helmets, other)"

My primary lock is fixed to the bike frame and locks the rear wheel, it's completely unobtrusive. My secondary lock is a chain lock, which I carry wrapped around the seat post, again completely unobtrusive, it just stays with the bike always.

My helmet either stays with the bike (if it's in a shed or the weather is nice, secured by the chain lock that also secures the bike to a fixed object. Or I clip it to my messenger bag, or simply carry it with me, it's very lightweight. Or you could do what most casual cyclists do, and not bother with a helmet at all.

>"they need ongoing maintenance"

I do basic maintenance with tools everyone should have in their house anyway: Screwdrivers, hex keys, pliers and old rags. The only stuff I've had to buy specifically for the bike is chain lube, and you could get by with something like household 3-in-1 oil. Or just not bother at all, and get the chain replaced every 3-5 years or so.

The maintenance needs for a commuter bicycle are very light. They're literally designed to be dependable and low-maintenance.

>"they don't go well with nice clothes and tend to require places to change, carrying a change of clothes, or even showers, after any but short journeys in mellow weather."

Even when it was ~35C here during the summer, I never needed more than to splash some cool water in my face, and maybe change my t-shirt to a fresh one. Most workplaces here have lockers and showers, because cycling is so popular, they're mostly meant for the hardcore lycra-clad cyclists. Ordinary commuters simply ride in their work clothes or whatever, no problem at all. Take it easy, and you won't sweat. Or get an electric bike, they're becoming very popular for this reason.