Bitcoin Cash was born out of the frustration of increasing fees in Bitcoin Core. In short, the growth in fees arise from too many transactions competing to get into each block on the chain. Airplanes in the holiday season or Bitcoin, it's the same. It used to cost pennies to transact a Bitcoin, not anymore.
So what's the biggie? Just increase the size of each block and let in more transactions, the fees drop and we are all happy right? Well that's the path that Bitcoin Cash has taken, but the counter argument is that larger blocks will create a bigger blockchain that will eventually prohibit all but the largest organizations from being able to run node. There's more to it than that, but there's the dilema in a nutshell.