During the takeoff roll, all four hyd pumps illuminate low press at about 100 kts! (B733)
If my memory serves me correctly (it's a long time since I flew these) you might not have any thrust reverse/nosewheel steering, etc. and you may, depending on how/when/where the hydraulic failure(s) occured, be left with compromised braking. Hardly a good configuration to have the airframe in for an RTO on what might be (and probably will shortly become) a limiting runway!
It seems to me that the more modern an aircraft, the more warnings are inhibited in certain ways during the latter part of the takeoff roll and the first bit of flight. This has obviously been a conscious decision on the part of the manufacturers, backed up by decades of data. Certainly the industry has become more "go minded" since I began flying and there are many examples to support this philosophy quoted by the proponents of this cause.
I think it's very difficult to assess the effect of an unusual problem on a) continued flight or b) stopping performance and to make a judgement as to which is the safest option, all in a few seconds. I would go as far as to say that unless you have grave doubts about the aeroplane's ability to fly, you are giving yourself a better statistical chance of success by taking it into the air and considering your situation there.