In a structure with no antes, you will only lose 1.5BB per orbit if you fold all of your hands. This structure allows you to play really tight, since there is time to wait for premium hands.

But when the antes kick in, you are putting in more money per orbit. There is no time to sit and wait for premiums. You have to play more aggressive.

This makes sense when we look at the 2 extreme sides of this. When there are both no antes and no blinds, correct strategy would be to only open aces. And when a big blind is as big as your stack, you have to play nearly 100% of your hands.

To conclude: the lower the blinds and antes relative to the effective stack size the tighter you should play.

Note: just because you should does not mean everybody does it. When people play too tight or too aggressive, you should still always punish them.

In a structure with no antes, you will only lose 1.5BB per orbit if you fold all of your hands. This structure allows you to play really tight, since there is time to wait for premium hands.

But when the antes kick in, you are putting in more money per orbit. There is no time to sit and wait for premiums. You have to play more aggressive. Also, like Dr.drfbaglll pointed out, there is more dead money in the pot. So being aggresives and winning pre-flop is a big win.

This makes sense when we look at the 2 extreme sides of this. When there are both no antes and no blinds, correct strategy would be to only open aces. And when a big blind is as big as your stack, you have to play nearly 100% of your hands.

To conclude: the lower the blinds and antes relative to the effective stack size the tighter you should play.

Note: just because you should does not mean everybody does it. When people play too tight or too aggressive, you should still always punish them.