Secondly, even if what you claim applies to Toyota cars, there are "better" cars to which it does not apply, for example a 911 with PCCB (ceramic brakes). These brakes will definitely overpower even a 911's engine, and will not fade with extended use. And I'm sure the world of cars is not bi-polar with Porsche on one end and Toyota with everyone else on the other. There's got to be a continuum where some companies design more safety margin into their products and others less.
Who should be blamed for allowing OSes to be so easily attacked by viruses? Microsft, who else?
Are there better OSes than Windows? Definitely, almost everything else is.
Does the fact that most computer users use Windows make it a good OS? No.
Does that make Microsoft a good or bad company? I would say it's an okay company for their shareholders (very good for the founders), but not so good for computer users.
How much of this analogy can be applied to Toyota? Well, you decide...