Visitors, Developers, or Machines
Garrett’s observation is spot-on here:
I’ve been trying to understand the appeal of these frameworks by giving them an objective chance. I’ve expanded my knowledge of JavaScript and tried to give them the benefit of the doubt. They do have their places, but the only explanation I can come up with is that developers are taking a similar approach as Ruby and focusing on developer convenience and productivity. Only, instead of Ruby’s performance being tied to the CPU level, JavaScript frameworks push the performance burden to the client.
In both cases, the tradeoff happens in the name of developer happiness and productivity, but the strategies have entirely different consequences. With Ruby, the CPU is still (mostly) the responsibility of the development team, and it can be upgraded. With JavaScript, the page weight becomes an externality pushed onto visitors.