There are two competing ideas about normals.
It is important to consider the fact you are using up at least 20 minutes of your life and in the high pressure games typically closer to 40 min. That is time they cannot get back. So it is important to be trying to win. Now I don't believe this is the case for you but there are some people that use "support"
build full AP and if you call them out will say "its normals bro". It really isn't fair to handy cap the whole team like that.
However, where the hell else are you ever going to learn a new champion?. You have to learn somewhere (Bots don't count I can just dive three towers and never die) you have to have somewhere to fail and learn. I have been learning to play
and you should hear the abuse I get every-time I miss an ultimate... it was even worse the time I actually told them I was learning... like this is something super champion specific I have to learn, the travel time the knock-back range... everything about the skill. There is no generic league skill in throwing Gragas ultimates that I should automatically be pro at.
In one of my more recent gragas games, my jungler Lee Sin was camping my lane for me.. which is great, we both had plenty of kills.. so we go for the tower dive. I throw the Ulti he jumps in and kicks him out of it and our target escapes.. he says I should of ultied first... I had to tell him they nerfed the skill that it has a cast time now so I did use it first or a similar time but it didn't land until he already performed his skill. Then we try again I try to throw the ulti in to kill the enemy... they engage on me dodging it... lee goes in under the tower and dies. "You missed your ulti!", "no he dodged it, you didn't have to go in just back off and wait for it to come back again"
I don't know why anyone would expect all their teammates to be perfect players able to read their minds and know exactly what to do or what they wanted. In an ideal world the best way is to literally go through everything in simple words for your team the whole time.. but that bruisers egos and is patronizing and they'll resent you for it. So instead you just have to plan for your team to screw up... always have an escape if it all goes wrong.