I'm sure everyone who has ever looked at C macros has thought the same thing. It's a great theory.
In practice, having macros will lead to someone abusing them and eventually, that abuse will be become institutionalized.
Don't say "it could never happen here" because it can and it inevitably will.
I don't have a specific problem with all of this, except I keep thinking a better solution would be to hammer browser manufacturers to keep their shit up to date or explain why they are not doing so.