You're focusing on one very specific thing, biking and walking, you're not wrong about the facts but of course what works in Texas doesn't work in Alberta. But the problem remains especially for the people who can't afford cars or can't drive them. For instance, if you have a seizure you're not allowed to drive for 6mths, so I guess if that develops for you and you're one of the 45% of the country with no transit options you're just fucked? Source

So yes you're right in part biking probably isn't the going to solve a Texas transit issue like magic or even be as big a portion as other places. But like there are trains and subways and busses and street trams and so many other solutions that are better than cars.