Most of us are just happy that Holy is "better" than it has been since the end of BC. At least it's a whole spec and not a crummy renew bot now.
If you really want the "cons" side of the story:
-In HFC we're still dealing with crappy itemization. Bad set bonus, bad trinket. Your Spirit and Multistrike likely got changed to a whole lot of Versatility.
-We're not very mobile. Leap glyph is gone. Our only movement abilities come at the cost of our only personal CD. Our instants are cd's (holy words) or really bad (renew).
-Speaking of CD's, we have no DR CD's at all, either personal or raid, and Focused Will now only triggers on melee attacks so you are super squushy.
-Blizzard keeps nerfing our single target heals for some reason. I still haven't seen any justification for this in logs and certainly not from Blizz, but they keep doing it. Renew got squashed. Flash Heal and Heal have gotten like 3 nerfs in a row now. Guardian Spirit talent got nerfed, etc.
-Our talent tree is a hot mess compared to the other healers. It looks like someone shook up a regular healer's talents and let the pieces stay wherever they landed. Where is our utili-tier? Why is Symbol of Hope competing against Light of the Naaru?
/grumpyoldveteran mode off
It does get better in Legion though. Holy really needs the new healing paradigm before it starts to shine. If everyone is either full hp or dead, Echo of Light becomes ubertrash. At 110 that's no longer the case.