There is no doubt that you are safer on the ground than in the air and an abort at 80 or 90 knots is no drama in terms of speed, runway etc.
Not necessarily. A big aircraft accelerating and approaching 90 knots have a lot of energy to get rid of. Rejecting a take-off is also a manoeuvre generally only practiced in the sim every very months where as a take-off is one that is performed every flight - a process that we perform virtually every day. Also, lightweight twins can have such rapid acceleration that you could be travelling well in excess of 100 kts before a stop is initiated. The time when a reject is a probably a good idea is when you are PNF and the PF incapacitated - but even then, a stop may not always be best. Highly prescriptive company (rather than manufacturer) SOPs that say when 'X occurs, take Y action' (in every case) are not based on 'good science' but often a 'good idea' in a training meeting.
I fly approximately 500 flights per year. I'll suggest that the '80 knots' call is called late, say five-ten times every year? I'm satisfied that continuing in each occasion was the right thing to do. The reason for the omission in most of the cases was distraction. And that's because we have fully functioning, thinking, human pilots. We should also consider the detrimental effect that such a policy will have on all other callouts. If our 'hair triggers' are set with no flexibility, a tendency will creep in to always caling early - thus removing the value of every call. I remember a former colleague who you could goad into calling "One to go" nearly three hundred feet before 'one to go.'
I'll stay with the imperfect way I handle these cases because I believe this is the safest thing to do.