But you get to have a SHIELD. I respecced 1h/shield last gen and loved it, and I'm going 1h this gen again. The problem is a lot of shielders try to play agressively like 2h and polearm, which is something the build is not meant for.
The shielder is a team player, do not aim solely for kills, but support your teammates. Remember, your shield is an effective weapon in team battles too. You do not always have to attack to help out your team, simply facehugging while blocking is very powerful when you have a teammate helping you.
When you fight, play defensively. You don't always have to match your opponents swings hit for hit - don't let go of your block simply because you just blocked your opponents previous attack. Swing ONLY if you are guaranteed not to be hit, through timing and footwork. Have patience!
Shielders have AMAZING survivalbility, provided that you constantly keep up your situational awareness. A shielder can survive being outnumbered and surrounded much easier than a 2h/pole. When confronted with an angry spammer or a mob of angry spammers, don't be afraid to turtle up and retreat, causing the enemy to teamhit each other while you wait for your team to reinforce you.
The reason 2h/pole seem to be better than 1h is because its easier to get kills with them as a newer/noobier player, and generally, that composes most of the players in a given server. However, a good 1h shielder can do just as well as a good 2h/pole. 1h is not worse, just harder to master.
tl;dr - LEARN TO PLAY