I haven't had the longest career, but the little I have see empirically confirmed to me that there's actually a strong connection between engineering culture and business success. Of course, a great engineering culture alone is not enough, but it can act as multiplicative factor.

In an engineering centric product. Why would a mom and pop email / news / casual gaming portal succeed directly because of good engineering? Time and time again we massively over-play our role in many business stories.

This is so true. For a website so heavily focussed on content, tech is only a small part of the game. Case point is youtube, though the tech challange with youtube is more complex. Nevertheless, youtube now has to survive on business deals and cannot depend on tech alone, unlike google search.

Yahoo mail was garbage. News was not useful and mostly ads. Search was not great.

If you build crappy tools don't be surprised when people don't find a lot of value in them.

I would think they aren't all that correlated. Look at apple, Steve job treated some of his engineers like crap and they were successful. Its nice to have a good place to work, but I don't think it ensures success.

This doesn't necessarily mean a 'bad culture' -

a) the concept of 'tough love' is applicable

b) were engineers allowed and challenged to innovate? or did their work effort primarily consist of navigating red tape and beurocracy to the point that all creativity was crushed?

etc.

see also: dilbert.

To me a good engineering culture isn't a "nice" engineering culture, it is one where the company consistently delivers outstanding work that is on point with business requirements.