The EAV model is an anti-pattern when attempts are made to apply it as a 'more flexible' replacement to a proper relational design. There are certainly places where it shines, for example in modleing sparse attributes, but they are niche.
This article, and moreso the ensuing comments, parses the issue apart quite well:
There are no special teachers of virtue, because virtue is taught by the whole community.
--Plato