Are companies that aren’t publicly traded more likely to treat customers as a primary stakeholder ?

When a company is publicly traded , they are legally fiduciarily responsible to shareholders which means they're more likely to view consumers as means (means of revenue) rather than an end in itself and seem to be more likely to put less effort into quality of products and monetise them much much more. But If a company isn't publicly traded then their main stakeholders are likely to include their direct customers along within any banks or partners

Is this a sound premise with evidence to support it ?