Earlier quoted context omitted.
This argument is useless since polynomial time is just as intractable as exponential time if the exponent is large. For example, lets say that we found a way to solve all np problems in n^1000 time, would that change anything? No, there aren't even 2^1000 atoms in the universe so we will only be able to solve it for the case n=1.
Your argument supports the view that P is a useless concept, not that that argument is pointless.
A good argument can be provided by an analysis of statistical thermodynamics gas laws. It highly disturbs some people to think that atoms being in motion implies that all the oxygen atoms in the room air might coincidentally cluster into a small corner of the room leaving the victim to suffocate. There is no reason to think that impossible under most thermodynamics theories. However, it is nearly infinitely unlikely and you'd merely have to wait a ten to the hundred times the lifespan of the universe for it to coincidentally happen. I suppose it scales quite strongly with room volume and linearly with air pressure, you have one atom in the ISS airlock and being in one half the air lock at any given moment is a very predictable 50:50 odds...
Likewise if the smallest polynomial solution to a NP problem takes a google's worth of universes to calculate, then even if it is poly you need not worry too much about mere human inconvenience.
I'm not saying its a wise way to go thru life, but there exists a large set of people who get hung up on whats convenient or beautiful must be right, even if whats right turns out to be very ugly or inconvenient, so for them "P=NP but your bank account is still secure" is a very big deal.