Pancakeswap and burgerswap are 1 on 1 clones of Uniswap. Yet uniswap isn't getting bleeded by this attacks. Why? Because gaps on infra layer (the blockchain) have been filled on ETH, but remain on BSC because the devs are clueless
You can't completely put the blame on BSC smart chain network for any reason, these dex built on BSC are to be blamed for developing vulnerable platform for their customers, sushi, bzrx, and other ethereum based coins and projects were also hacked, this doesn't mean bsc as a whole is full of vulnerability, that's not true.