Agreed, when I see an opinion like no product input from the tech team it just makes me think that the company in question would just be better off hiring contractors.
Why do you think a developer should have decision making power in the area of design? They are not trained in design and UX. Conversely would you be ok with designers or other non-technical people dictating technical decisions? Of course not!
But as a consultant, I want to actually get paid, and paid well. If I work on ill-conceived design put together by an incompetent product team or an inexperienced founder, I'm also much more likely to have to push hard to get paid for each milestone. So I only consult when it's clear that I can add strategic value and that my client really understands their market. Once I'm sure those conditions are met, I can help them on the technology side.
When I ask my clients probing questions about their product plans, they generally seem quite happy that I care. And yes, I have advised some of them that PHP would have been a terrible choice for their technical requirements. A large part of the value a senior consultant brings is knowing how far out on the bleeding edge is wise for a given company, product and team. You want a good balance of development speed and a reasonably mature ecosystem.