This isn't "selling fear", this is common sense. This isn't about sending transactions without a fee, this is saying your transaction may not make it in even with a fee. Get the premise right before you decide you're disagreeing with it. Full means full. As in wait for the next one. And if that one is full, wait for the one after that. How long do you think people will wait before complaining that Bitcoin is slow and useless? Bearing in mind this is the internet and people complain about the slightest little inconvenience like it's the end of the world. I don't want to see the outcome of that fallout.
OK, lets get the premise right. If we ever get to a scarcity market for transactions, it might look a little more like this:
1) Your client would inform you of the amount of fee you should include if you want your transaction confirmed in an average of X-minutes, where you can set X. If you want it faster, or guaranteed delivery, you pay more. It becomes an auction market with a new auction every 10 minutes. Full means full *at that price*.
2) Service Providers and high volume transaction businesses will increasingly do a lot of off-chain ledger-ing (maybe with side chains) and less frequent settlement transactions on the block chain.
3) Back door off-chain payment deals (maybe in fiat) will be made by some high value transaction makers to get preferential treatment by their favorite miner (who is to say that this isn't already happening?)
4) People will save transactions for off-peak times, and combine transactions to economize.
5) Others won't care and will just pay 'whatever'
6) Lots of folks on the internet will complain.
Bitcoin would probably grow a little slower, but please realize that this is an endurance race even though sometimes it feels like a sprint. Bitcoin can never lose by growing too slowly, only by growing fatal flaws. It is worth it to be careful.