problem with sarcasm

My problem is, sarcasm doesn't mean
how they always said it  
when I was a kid.
Like Steve Martin's "Well, 
Excu-you-ooze ME!" or "Yeah, that's
perfect, put that right there." - when
somebody's dropped some smashed or
dented thing. Something loud, at any
rate, that wild and crazy guy 
was not really asking
to be excused, was he?
Nor did mr. perfect-right-there
mean it, dudes. 

Which was plain to see. 
That, friends, was sarcasm.
Something said, and 
perfectly clear: not meant. 
At least, intended as such: to be understood
as a dig. A jape. A wry and bent 
sort of poking instrument, to jab,
jab wry between the ribs. That is, 
or used to be 

the sense of it. 
My problem is 

lately, the dictionaries 
all seem to insist
it's malicious or cruel!
A conspiracy! Only guess 

I've got: lexicographers 
must have been wimps at school. 

'Cause if that's what sarcastic means 
to them,
then 

I kid you not.
I pity the fool. 

"Good job." 
Sarcastic good job, 
how malevolent, oooo.