In a podcast Casey Rodarmor used the analogy of a bus that let's anyone ride as long as they pay a fare. Even if we use that analogy ordinals are like filling up the bus with beach balls instead of passengers. Even if you're paying the fare people who want to use it for actual transportation would be completely justified in banning that type of behavior.
Discussion
No. Eventually the beach balls will have to pay a higher and higher fee. If ordinals are useless than it will become less and less worthwhile to pay for. The protocol designers from the start expected blocks to fill up which would drive up fees which would support the network.
You’re making the same argument big blockers made 5 years ago. There’s functionally no difference from saying “but what if there’s only room for 20 people on the bus then only rich people could ride it”. People even made bus/transport visualizations to make these points!
The point of the segwit discount and how inscriptions use it, is that the beach balls are actually paying a lower fare for the same amount of space than actual passengers. The danger with inscriptions is not that they might be displacing “useful” transactions, but that they are polluting the blockchain and now all full nodes will have to spend more resources (cpu, hard drive) to validate and store those transactions. In other words, they are destroying the commons.