Entirely depends on the person. Numbers are linear, regardless of they go negative or stay positive. Remember way back in elementary school days, when they had you plot out a line with 0 in the middle, and dots going each way left and right to teach the concept of negative numbers? -5 and 5 are 10 steps apart. so that's pretty simple to take 10 away from 5 and get -5 as it is to take 10 away from 15 and get 5. You're moving 10 steps to the left either way. To me, that's a lot easier and faster than starting at 13 and adding 16 to it, because you're moving 16 steps. Having 1e's AC system locked to a 20 point range is simpler to me, even with negative numbers, than having a scale that went past the 40s possibly.
I totally get how this is subjective and based on preference. But I disagree how the statement "ascending is easier" or "makes more sense" is being used as if it were something objective. Sometimes it is, sometimes it's not. Usually when I see someone make that comment in the context of how ascending is better than descending, they are omitting things like how 1e had it locked into a 20 point range and other editions do not, and omit things like how you only ever had to make one math step in 1e (since THAC0 was pre-calculated) and in 3e (when the switch was made), it was not because more factors were involved in each attack, and those varied in each attack. I.e, all things being equal, ascending is more intuitive for most people, but the fact is, not all things are equal when comparing 1e to say, 3e. There are additional layers in 3e that make it more complex.