BEags
t's not so much the inconvenience of not being able to use the laptop etc in flight - it's the risk of their loss or damage in hold baggage. Many business travellers also have sensitive commercial documents with them which they are unlikely to wish to lose sight of.
It's both for me. I also do quite a bit of work in flight, dealing with emails (for transmission on arrival), expenses, quite often reviewing materials etc, occasionally doing some billable work.
I probably average 1 hour per flight (most of my flights are 2-3 hours duration.)
Multiply that up by 80 flights per year (I probably do more than this) and I've just lost 2 working weeks.
That is many thousands of pounds of lost billing opportunities, as the work has to be done sometime and doing it on the ground eats into potential billable hours (I am a freelance consultant.)