From the very beginning, Your relying on them for your W attack speed, Your passive % damage and your ultimate. If they afk or just troll it really cripples any impact that Kalista has to offer in a game. Yes I am tilted xD, but that's beside the point that items like 
or 
have time limits and then it allows you to change your partner so why let her be so limited.
SOLOQSUPERHERO2 votesAgree and I don't play Kalista.
You could argue though, that this could give too much power to a different lane without sacrifice to her own lane
Teémò1 votesI don't see what's to argue, if you bonded with the jungler, you'd only gain ur passives and ult when he is there, and the bond mark would show if they are nearby. Beside that it has nothing to do of lane faze as it should be over. There wouldn't be any power change as the support would have the same effect. The only difference being you could save say your mid laner with your ultimate. Though now you can't save your support anymore. and if it's not worth it then why enforce it.
SOLOQSUPERHERO1 votesMy point is let's say you have someone who synergizes really well with Kalista ult, like a mid lane annie or a midlane morgana. They do lots of damage but lack a gap closer/survivability when they go in.
Kalista being able to change who she bonds with enables her other teammates in a way before; where right now she could do this if she wanted to, but her lane phase would be worse for it as she won't get her W proc and won't get her ultimate until you group. This would remove that punishment.
Teémò1 votesIt's a team game though, if an adc is trash and considered useless by the support he will roam and try to relevant elsewhere. If the support is useless to the kalista and refuses to cooperate with the kalista then she also becomes irellevant. Your thought isn't wrong, in truth it is her own ultimate, and like any other ultimate it should have an impact in game. 
can always bring someone with him and can swallow anyone on his team to protect not removing stealth. The attack itself doesn't really do damage, And the Range with it is the same as Annie ulting with tibbers. It may get her closer, But the end effect is the same as many adc's would have 
Where she would be able to get there in time.
With the 
changes coming she's going to be suffering somewhat. Though for certain I can say no champion's ultimate should have 0 use in game or lack the ability to use it. If you've ever had an afk support as kalista, or mordekaiser it's probably one of the worst feelings.
reaperteaser1 votescan you not buy another black spear in the shop?
Teémò1 votesYou can, but it won't bind you because the champion you applied it to is spell bound to it. like harry potter's unbreakable vow https://youtu.be/r_VS2B48c24?t=158
Nameless Voice1 votesSo, you want to be able to force an uninterruptable, insanely-long animation on your teammates at any point throughout the game?
Dynikus1 votesyou have up to 3 minutes to bind with someone, in that time you can buy another spear to bind with someone else. You can't change who you're bound to later because that could definitely be a bit broken. You could just pair with your support for the laning phase, than pair with your top/jungle front liners mid game and have broken engage. Or you could pair with your jungler halfway through the laning phase for easy ganks, then just swap back to your support.