I'm definitely not hostile towards out-of-band transaction systems. They're GREAT, if you trust the centralized resources that provide them. I'm hostile towards a hard permanent limit of 7 transactions per second / 50GB per year transaction growth in Bitcoin regardless of the growth of storage and bandwidth capabilities because some people believe that fewer total transactions of a less used currency (with then decreasing utility and value) will somehow make themselves more money, perhaps, in the very short term until the system dies.
Buy hey, at least you can run a full node on your wristwatch!
IIRC, that 7 tpm metric is a calculated max rate based upon the current average transaction size and the 250KB soft limit. The hard limit is currently one MB, so we can presume that 28 tps or so is the realistic limit. This doesn't sound like much, and it's not really compared to payment processors such as Paypal. However, as a payment processing backend network, comparable to ACH, it's not really bad and it's a couple orders of magnitude cheaper.
The real question is, does the main bitcoin network really need to support such transaction rates? I would argue that it does not, and that I'd give even odds that a one MB hard limit wouldn't result in catastrophy. I would also argue that a 10 MB hard limit, which would put us up close to paypal, isn't a bad plan either. Keep in mind though, as we raise the limits, the theoretical resource usage by the network goes up exponetially. We need out-of-band networks in order to fulfil Bitcoin's original promises. They have always been expected to develop around the main network as the economy grew, we just can't really predict how it's all going to play out. Free markets are like that, efficient because they are unpredictable.
And if you can run a full node on your wristwatch I'll eat my hat.