Nobody said the growth would stop, what has been said is: hitting the blocklimit will not cause big trouble because the first thing that would happen would be microtransactions for tiny amounts of money happen somewhere else. So all your doom preaching and urgency is invalid.
Hitting the limit will not render btc unusable - in fact it will clean the chain from spammy microtransactions.
That's funny. So here you are entering a store, present your creditcard to pay for your coffee..... But guess what? I'm sorry sir, your order is below 5$, you will have to fill up this special "Starbucks-card" first with at least 50$, since we don't accept 5$ creditcard payments here.
Give me one reason we would not allow micropayments to happen on the blockchain? They're all fee-paying-payments just like the large(r) ones. If you want the blockchain to be supported by transaction fees at one point you're going to need a lot of transactions.
Besides that, why put a hard limit on an open-market-concept? Let the market decide. If miners don't want to mine what in your opinion are "spammy" transactions then they wont. For the rest of us, let miners mine what they want to mine, in the end for the miners they are all equal in terms of transaction fees.