Wow, I can't believe so much hate for Tsubame. Tsubame literally didn't do anything wrong. What she's doing was "tried to reject but also not to hurt her friend".
Did you know? Many cases happen where a friend finally hate each other or at least not at speaking terms after one of them do some "sudden confession" ?
Actually, their relationship almost the same. Ishigami unintentional confession lead to this disaster. At that very moment (before misunderstood confession), they are a good friend. But suddenly got confession by your friend, can you imagine how you feels at that moment? Again, yes its unintentional, but its not like author dragging it too long with Ishigami straight knew about it and "GO" for it (to chase Tsubame).
Now, she tried to reject him by not hurting him. Thats the "basic" rejection if you want to "not hurt" your friend. And it depend on the person, if he really love her, he will notice Tsubame feeling, and tried to pursued her. If not, its end there. Even if she didn't use any "hope" word like this, Ishigami still chasing her. "Literally" Glasses Girl talk about it "IF Ishigami truly love Tsubame senpai, he will notice Tsubame feeling and not give up!!!" . Alternated route if Ishigami gave up, well, he's hurt and they will not friend anymore (or at least is there any arc to continued their relationship).
If I would like to choose, I like Tsubame more than Ino. Not only we got more development and progress between these two, we also got some of their perspective. And so far Tsubame isn't a generic Heroine. Meanwhile Ino, sorry to say this, she's just a generic heroine.