I agree, though it looks like the reason we do like this is because bottles use -mtune instead of -march:

```ruby
    if ARGV.build_bottle?
      append flags, '-mtune=' + map.fetch(:bottle) if map.has_key? :bottle
    else
      # Don't set -msse3 and older flags because -march does that for us
      append flags, '-march=' + map.fetch(Hardware::CPU.family, default)
    end
```

Bottles could just do a `gsub` on the returned value though.