OK, rant over, but the question remains.
Well, no. It really doesn't.
Ever stood between multiple closely spaced railway tracks with trains coming in both directions and had to figure out where to go to keep from getting run over?
With arriving traffic landing at 150 mph and departing traffic using the same runways, and taxiing traffic going every direction at once during normal routine business, one is faced with a spiderweb of taxiways that all look very similiar. Radio traffic is fast enough paced at KLAX that it's one of the few places where pilots don't even read back their clearance. Simply their aircraft number and transponder code...there simply isn't time to do any more...and pilots are advised as much over the ATIS information system.
Traffic moving to the runway frequently must cross multiple runways, or stop between them, and exiting traffic must do so at high speeds, often across other runways or to intermediate taxiways that separate them.
Runway incursions have been the hottest topic with the FAA for several years now. Because of the education effort and awareness campaigns, the number of incursions is dropping.
When landing and taxiing clear on a high speed runway exit, it's often difficult to tell which aircraft are where. If it were just one 757 to watchout for, that might be fine. However, there may be 30 757's, all moving in different directions, to say nothing of a seaof EMB-XXX's, MD-80's, 747's, 737's, 777's, A-320's, etc, all in motion. Some of traffic may be on the same frequency, but as one clears the runway, usually it isn't.
Runway signage and markings can be misinterpreted.
Devices such as illuminated stop bars are safet oriented, and have proven very helpful. Let's face it, we don't fly in a vacum. When we fly, we have an airplane around us, adequate radar and radios, engine instruments, airport diagrams, and even external equipment like airport and runway lighting. Stop bars are a part of this system, as are lead-in lights and stop bar lights. Tools for doing the job.