How do you tell who is a farmer and who is a miner with ASCII at a glance? Or which particular "s" creature that one is?
That's pretty specific compared to your original statement's generalization.
Farmer: Brown smiley face. I'll admit, you can't tell the specific profession, but I feel that the general class is good enough that you can tell from their location what kind of profession they have. That's just me, though.
S: Color, capitalization or no of the s, color of the s, and the location of the s should tell you the kind of creature it is.
The problem is there are a
lot of different kinds of farmers. Your haulers might be soapmakers from migration that are brown for lack of another color, your cooks and your brewers will look just like them. Your threshers and will be going to the same food stockpiles as your growers, your brewers, and your cooks, as well.
As for the "s", here's a list of all the creatures that have a lower-case "s" on them:
Rattlesnake, rattlesnake man, copperhead snake, copperhead snake man, slug man, snail man, sparrow man, skunk, skunk man, satyr, siamang, strangler, helmet snake, giant sponge, sponge man, frill shark, squid man, spiny dogfish, and maybe some other things I didn't get in a quick browsing. (And yes, there are color variations, but most of those are either gray or brown, anyway.)
With all that said, however, the largest argument for ASCII, that it is what you are used to, goes both ways. You're used to the thing you've used. You can have any arbitrary system that you create yourself, and get used to it, so being used to something is not an argument for anything except that you just don't want to learn a new system. That, again, does go both ways to anyone who doesn't want to switch what they're used to.
The arguments about overlapping tiles (as cephalo mentioned with the volcano looking like a trap) or the arguments about how much data a single tile can display at least have merits that go beyond what you, personally, are settled upon in terms of being a way to actually convince other people.
If you are arguing for your particular system just because it's what you're used to, then you are effectively just affirming the choice of the people who are already used to a different system to not even bother considering your system's merits.