You've got it backwards; they didn't "kill it" on SEO by making good content, good content was rewarded with high ranking search results. Even this is questiona

You've got it backwards; they didn't "kill it" on SEO by making good content, good content was rewarded with high ranking search results. Even this is questionable now that google et al purposely present just enough of wikipedia's content directly in the search results to discourage you from leaving google. So in the end they (a) display ads and (b) don't get the revenue. THis is a win?