Well, asm.js gets around this by piggybacking on JavaScript's syntax. So that's one approach.
Adoption really is a big issue, and I think it kind of misses the point to handwave it by saying, "Oh, adoption is such a big issue that it's insurmountable, so let's ignore it." Google hasn't really done a lot to work with anyone else on PNaCl, or even really to address any issues anyone's brought up with PNaCl. They're just sort of creating an island so far. If PNaCl is going to be a thing, they're going to need to get past that.
Adoption really is a big issue, and I think it kind of misses the point to handwave it by saying, "Oh, adoption is such a big issue that it's insurmountable, so let's ignore it." Google hasn't really done a lot to work with anyone else on PNaCl, or even really to address any issues anyone's brought up with PNaCl. They're just sort of creating an island so far. If PNaCl is going to be a thing, they're going to need to get past that.