> the phrase "avoid success at all cost" in a certain context which may have had some role in making Haskell seem Ivory Towerish.

This phrase is often misunderstood, it's "avoid, success at all costs", not "avoid success, at all costs". In other words, don't optimise for mass market adoption at the expense of everything else. Languages that have arguably done so, have ended up as extremely complex and ridden with corner cases.