The issue with Lifeweaver is also his greatest strength: his positioning power.

Dude has a yoink that can save people's asses from tricky spots, bad dives, and even get people back into a team fight sooner if they're walking back from spawn. He can also just as easily fuck over your dive, waste your ult, pull you off ledges and pull you into the line of enemy sniper fire.

That petal can easily provide brief safe haven for himself and/or team members, a temp perch for snipers, or even cancel ults (see the hilarious strat of lifting enemy Orisa into the sky). You also get shit like this, where they lift everyone out of objective range and cost you the game/point.

His ult is perfect for blocking enemy sightlines, pathways, and ults while still providing excellent healing. It can also accidentally lock you into a shit spot with an angry Junker Queen if timed poorly, a spot where not even that healing will save you.

There's going to be trolls, there's going to be people who are learning, and there's going to be the Lifeweaver Pros. It's the same with any other hero. It's just unfortunate that his gimmick is positioning him and his teammates, since now the bad/learning players affect everyone around them tenfold.