I don't think anyone is shoving anything, especially barrier, down any body's throat. Well. Last night maybe. But not right now. Well.
That said I don't particularly love that the spirit tree (arguably the most interesting, lore-wise, school of magic) and our only non elemental tree is designed around barrier production nor that barrier-dependent passives pop up in other trees, encouraging you to make 1/8th of your spell line-up. It feels like it's verging on being a "core" mechanic of the class, so having one ability that focuses on it is a bit strange. There should be more ways to generate Barrier outside the Spirit tree if there are going to be barrier-dependent passives, just the spell Barrier should be the simplest, most reliable way to do so.