Why do NOTAMs consist of code instead of plain language? I'm currently getting thru a PPL course book and I don't understand this. Is there any purpose of sending NOTAMs in this format:

"RWY 08R/26L DUE WIP NO CENTRELINE, TDZ OR SALS LIGHTING AVBL"

instead of plain language

"For runway 08/26, due to work in progress, there is no centreline, touchdown zone or simple approach lighting available"

Why do they force pilots to learn common ICAO abbreviations when they could simply send the text message without encoding it? The same questions goes for TAFs and METARs.
The NOTAM format is from the time when people still would call the value of individual bits over a phone line. 

Ok, that may not have happened, but my point is that data transfer was incredibly slow compared to current day standards. Therefore a compact format saved significant  transmission time and cost without losing any information. The format didn't change since.