Gem, as the control deck you basically forfeit all of your tempo in the early games anyways; and your goal is to kill theirs. If the opponent casts a 2-drop on turn 3 because they play around Censor, you already slowed them down in a sense. Furthermore, it's not like you're only relying on Censor, but have multiple things to do (like, cast a removal spell or
Telling Time). Heck, if worst comes to worst you spend 1 mana you held up for Censor to cycle it away.
My reasoning for the card being more situational is that by far not all of the decks curve out perfectly and I can picture quite some occasions where you'd just want a Telling Time instead (which, remember, Censor is competeing for slots). Two examples:
-Control mirror. Nobody plays spells before turn 5-6 except some occasional EOT carddraw/filtering. Here's where I'd rather have Telling Time EOT than cycling Censor.
-Aggro match-up; your opponent plays two cards a turn (2-drop + 1-drop turn 3, 2-drop+2-drop turn 4). Instead of countering one of the drops using Censor, I'd prefer Telling Time to look for the good cards in this matchup (sweepers, removal, lifegain) instead of countering a cheap spell using Censor.
There are quite some match-ups in which Censor is better as well (preventing a t3 Tutelage/Fevered Visions/Liliana instead of having to draw into your Unmakings is HUGE). Big point here: Censor is good on one, maybe two turns in all of these matchups. I agree that advantage is quite big when compared to the advantage Telling Time has over Censors cycle, but there are too many more instances where you have that little advantage that might make the difference that it's impossible to make a definite call on which of the two cards is better/which balance of them you should run.