Could ARG_MAX be increased?

Currently, ARG_MAX is set to:

$ getconf ARG_MAX
65536
 
in syslimits.h. This is quite low compared to other OS (SunOS has 1MB
IIRC, and OpenBSD 3.5 256K) and causes the "argument list too long"
issues when for instance grep'ing in directories with lots of files.

Last time the limit was upped was ten years ago:

"Revision 1.4 / (download) - annotate - [select for diffs], Mon Aug 8
09:12:43 1994 UTC (10 years, 1 month ago) by davidg
Branch: MAIN
Changes since 1.3: +2 -2 lines
Diff to previous 1.3 (colored)

Increased ARG_MAX even further...to 64k bytes."

Is there a reason for keeping ARG_MAX so low, or could it be increased
to eg. 262,144 bytes?

-- 

Juha