Surely the main issue here is that the damned thing could fall off and kill someone?
250 grams or so of camera from 1000 feet - that's quite a big hole?!!
The airflow interference with a static port or pitot tube is perhaps valid (although you'd have to be an absolute goose to mount it near either) but they're hardly going to contribute to a stall or some other drastic airflow change are they?
They're great things - we suction mounted our one to the inside of a 152 windscreen to get a shot of our 11 year old boy's first flying lesson.
But personally I think anyone other than a LAME who mounts a Go-Pro on a wing or the fuse is bloody nuts!
I've read anecdotal stories of people using the Go-Pro supplied suction mounts to do so... I hope to God they're not true.