So many sites these days are so bloated and slow as to be unusable. Those of us devs who chose the other approach have to work harder no doubt but our users are much happier. Isn't that the goal, after all?
My current users value speed of feature release over almost anything else, because the system needs to adapt to their rapidly changing business rules.
In my previous job, correctness was the most highly valued attribute, followed by adherence to consistent design across the org (which was large, and produced many sites that a user would navigate between all-but unknowingly).
In either case, if I'd gone on a HTML purity rampage, I would not have been helping my users in any meaningful way.
So many sites these days are so bloated and slow as to be unusable. Those of us devs who chose the other approach have to work harder no doubt but our users are much happier. Isn't that the goal, after all?