It's not an "attack", it's pure competition in a free market. If bitcoin fails to scale (and it now looks like it will NEVER scale), then it must expect that investors and users move to other coins.
The thing is, Bitcoin Cash doesn't scale well either. The bigger the block size is and the shorter the block time is, the more network bandwidth, computational power and storage space is required to run a full node, especially under the full load. And systems that get too demanding to run under the full load cannot be described with words "scales well". This is particularly true for decentralized systems. Empty mempool is not everything.
The thing is that I dont't trust bitcoin cash and I won't ever buy it. Maybe, I'll mine it, if it's profitable. Otherwise, there is no reason for me to invest money in it. It's very risky.