The count is actually imposed by the inventors of SMS who decided to make a 140 byte maximum per message. Well I guess you could argue that it's still self-imposed since it was Twitter who decided they wanted to build everything around that limiting system, but they can't just ignore HTML characters for the count as someone other than them is doing the count.

Note that there's already been some counterpoints against this story posted elsewhere on the internet:
Counterpoint from John Gibson
Counterpoint from Derek Smart

In addition, the reward is far below the cost of the processes needed to retrieve that data, so no one's going to bother for that reason as well.

And this attitude is why no one likes Wikipedia. Good job driving away the people you're "helping" with your deleting.