Let's imagine you have a shop, you've invested a lot of money into the business and it's in a great location.

You have a problem, your footfall (people going into your shop) isn't what you want it to be. You have a brainwave - change the window to display something you now lots of people will want. 

As you attract more attention and people decide to enter your store as they point to the window display, you stop them.  You tell them they can't come in until they give you all their details, including a mobile number and email address. You wonder why most of them turn around and disappear down the street - you may as well charge and entrance fee. You are putting people off.

That's what happens when you think waving gated content about will give you more visitors to your website.

It's out of date, ineffective and gives people a reason not to engage with you, Don't be fooled by conversion rates - they mean nothing if people don't spend any money.