Opinions on Ardent Censer

Ok, as a support main this fascinates me this is either an amazing item or a "omg most noob item in the game you suck if you build it". I have never understood why people would hate it on janna and sona and the people can never give me a reason to why they think it is bad. Janna and sona can both get the 25% attack speed on an entire team sona more than janna but janna still has every e. I would like to have some reasoning as to why some people hate it so much as it in my experience has been able to change fights dramatically in our favor.

[Item stats] +40 ability power +100% base mana regen +10 cooldown reduction unique passive: +8% movement speed unique passive: heals and shields give on another unit grant them +25% attack speed for 6 seconds.