I'd spoken to contractors who buy tools at HF for a single job, then return them after the contract, if they are not busy. The problem is if they are busy, they don't have the time to go back and forth, and a tool breaking on the job before completion cost them more in the time it takes to drive to HF and replacing the tool, even for free.
Overall, they get tools they know gets the job done right because their reputation of good work is at stake, and the contract time pressure to complete a task keeps them from using cheaper tools of unknown quality. The good tools are part of their toolbox, and thus are ready to be used, and more importantly, trusted to be used, on demand.
So despite the lifetime warranty, its not as often used as it appears at least by professional contractors.
Harbor freight has lifetime warranty on hand tools as well and they do honor it.