Shipments of microprocessors for netbook, notebook, desktop PCs and related x64-based servers and workstations flatlined in the second quarter as the economy stumbled a bit in the United States and Europe. Consumers held back on PC purchases while also spending some of their hard-earned cash on tablets. The good news is that …
"Flatlined" means DEAD. PC chip sales are far from dead. We don't need metaphoric hyperbole.
Which came first?
I'm almost sure I heard "flatlined" first in biz-speak, meaning zero growth (neither expansion nor contraction). Medical use of the term, in TV dramas, for a flat hear monitor trace (=dead) came later. Maybe the medics were using it that way a long time before the TV dramas, and maybe not.
Anyway, what's wrong with a word with two or more meanings?
Making up definitions......
"Flatlined" is DEFINED as succumbed, to kill, dead, no growth or progess.
Since there is cpu growth albeit slower, FLATLINED is NOT the correct metaphor. It is hyperbole.
Poets redefine words not journalists.
You never heard it used in "biz-speak" for zero growth. That was plateau. Flatlined refers to unresponsive or dead as relating to heart and brainwave monitors.
All synonyms listed by Meriam Webster relate to dead or finished.
"HISTORICAL DICTIONARY OF AMERICAN SLANG
FLATLINE verb [alluding to the flat line on the screen of such a device when vital signs cease] Medical (of a patient) to die while being monitored by an electronic device that measures vital signs.; (hence) to die. Also figurative."
And from William Safire thereby ending all debate:
"1982 “. . . ‘to flatline’ is to expire, a verb taken from the lack of activity on the scope measuring vital signs”—What’s the Good Word by William Safire, page 152"