I've been that engineer and with good reason. That obscure edge case which rarely comes up in production is very disruptive when it does come up. The product person waving it off is also not the one that will get paged at 2am to address the issue when it occurs. Accepting that 90th percentile use case is infuriating because it is tacit consent for an unfinished solution with the rest being made up later with additional toil, now constrained by load bearing things you cannot change. Thanks for rushing the thinking and making my life harder later for no reason.