Earlier quoted context omitted.
We had it raised to several thousand concurrent requests with no questions asked. YMMV based on age of account, amount of spend, etc.
Yeah, most of the limits are there just to prevent "whoops, we fired up 500 $2/hour servers and left them running all month, can you refund us?" sort of newbie situations. Very few are technological and AWS has been happy to bump them up for me in each occasion I've had a need.
It's not technological - it's about ensuring they have a reasonable handle on capacity and what they happen to have plenty of.
It's not a problem as long as you're not asking for astronomical limits, but people need to be aware of it and request increases in advance of starting to hit limits rather than assume it'll be near immediate to get them lifted.