The limit is to avoid mass PM spamming using newbie accounts.
Basically this.
Seriously though, there should just be a block option.
you can block PMs from
this page if that's what you're talking about.
That's a solution when 1 newbie (without limits) is spamming 1 member.
Now take 1 newbie spamming a PM to 100 members, or more.
More power to the Newbies, please.
Less power to the Newbies, for the love of god, please.
Btw, the waittime is not only in place for (low activity) newbies, but it's there for each and everyone of us (including posts, PMs and even reports iirc).
waittime = 360;
if(activity >= 15)
waittime = (int)(90 - activity);
if(activity >= 60)
waittime=(int)(34.7586 - (0.0793103 * activity));
if(activity >= 100)
waittime = max((int)(14-(activity/50)), 4);