Your impression is true, and there's a good explanation for it. In my experience, the cost of software failure is much smaller than the cost of hardware failure

Your impression is true, and there's a good explanation for it. In my experience, the cost of software failure is much smaller than the cost of hardware failure. If your software fails, your robot might behave erratically. No problem, just revert to the last stable version and try again. OTOH if there's a mistake in the hardware spec, you will have to replace that $5000 sensor, or worse, your robot might electrocute someone. End result is you can get away with shitty software, but you can't get away with shitty hardware.