But the OP is not proposing an absence of a block size limit. This is a straw man argument, and the fact that it's the second time you've made it, means you're being disingenuous.
But there IS a block size limit. It's only going to be bigger, but not infinite.
Increasing the limit to avoid raising fees is in effect asking for no limit, as the reason for the limit is to ensure sufficient fees are paid.
This is a valid point. As far as incentivising fees goes, a block limit that is always just a bit bigger than it needs to be, is functionally equivalent to no block limit at all.
And actually, I think I see your point that IF this were the only mechanism in play regarding how much people pay in fees, it could pose a problem. My counter is that it is NOT the only mechanism in play.
ETA: R2D221, hope this clarifies it for you too.