I don't get what's so wrong about poppy's ultimate.
I feel similarly but I play her every now and again.
I personally think that Trynd's ult is worse overall. Counterplay is a weird concept in practice though. I mean why is an AoE stun or knockup that hits all your team and leaves everyone defenseless against the entire other team better than one champ on your team being a wrecking ball when they can still run? Also Poppy's ult does let at least 1 person on the other team react to her. If poppy ults nami, nami can still bubble her or wave her (trading an ult for an ult is fair). So it isn't like there isn't counterplay, it just puts one person on your team on the spot.
I mean I totally get why counterplay is important to a game, but when you've got cases of this has counterplay where that doesn't is far more subjective. I mean if blitz grabs a nontank to start a teamfight, that person is dead and there's no way his team can save him short of blowing a lot of ults, even then it isn't guaranteed. If that happens, your team is left in a 4v5 that is difficult to counterplay. Yet that's considered fair by riot. So how is a team getting an advantage when someone fails to act (the person who got ulted by poppy) bad where one team getting a big advantage by someone failing to dodge (the person blitz snagged) good?
I'm not trying to pick on blitz, I just want to show how counterplay has grey areas in it. I kind of wish riot would come out and say these are skills we think have fair counterplay (trynd's ult) and these are the ones we don't (poppy's) so at least we could see their reasoning and pick their brains on that.
I guess this leads us back to what riot wants of her ult. Do they want it to be a dueling ult? Even though it isn't used that way, in a team fight her ult can be used to force a duel. Do they want her ult to be tankmode? Do they want it to be something that an assassin would love?
I can see why people hate it as it does give the poppy player a lot of options, but she seems like she was designed to maximize a player's options and adaptability.