I wouldn't say she bullied Cloud in AC. She was certainly harsh, but what she said had to be said.
He deserved it fully, I say. He needed that moment of realization.
The one thing that struck me as a bit insensitive from her at first is "a memory of us?", because it almost sounded to me like an ultimatum - Cloud's family or Aerith and Zack. Then I found out an alternate translation the original Japanese version of that line was something like "why do we have to lose out to memories", which I think made it a bit clearer she was trying to get Cloud to let go of his past in general, not just Aerith and Zack. Which is still harsh but less so, while the "memory of us" way it was phrased didn't sit well with me.
The thing is, Cloud's memories play a huge part of who he is. With the Dissidia dialogue and CoL it almost reminds me of Kingdom Hearts, how big a role memories play in explaining him and Sephiroth. I don't think he'll ever fully put his past behind him, one way or the other I think he'll always have Sephiroth's shadow over him. But that's fine - just because you can't leave your past behind, doesn't mean you can't live with it. And that's what Cloud does - he doesn't forget his past, he remembers it and lives for the present.
What Tifa's saying to Cloud is to stop living in the past, being a pain in the ass, and live on with the present. She's not saying that he can't completely forget about Aerith and Zack and be with Tifa, but what Cloud was doing in the movie was angsting over his memories, and Tifa
does what wants best for him. Hence the line, 'dilly dally shilly shally.' He wasn't forgiving himself, and Tifa stating, "a memory or us," only comes to serve that Cloud was living in the past, all these feelings of guilt for Aerith and Zack basically making him emo.
While I agree with this, I think you and I can both state that what Tifa did into saying, "a memory or us," does NOT MEAN that she wants Cloud to completely forget about his past. She's trying to get him to stop angsting and feeling guilt over his past, not forget about Aerith and Zack altogether. While one can remember their memories, it's no good feeling guilt over the past.