Well, you could point to the fact that there are alternatives to using "razor and blades". You can buy straight razors and re-sharpen them yourself. You can buy safety razors, which are technically still the "razor and blades model", but aren't based on proprietary designs, and just accept the added inconvenience that comes with.

And yet, still, many people choose to use "razor and blades" products because it's more faster and more convenient and requires less effort and lower buy-in cost than the alternatives.