It's pretty much entirely a factor of the frequency of the character. 纏 is a relatively uncommon character, and the word まとめる is often written in hiragana, so many Japanese people don't know how to write it. It has nothing to do with the *shape* being hard to write, it's just the commonness. (Of course there's a perception that a dense character like that might be harder to write, but Japanese people don't have any trouble with common high-stroke-count characters like 驚, and there are plenty of low-stroke-count characters that people wouldn't know how to write due to their infrequency.)
Last edited by yudantaiteki (2010 June 08, 7:28 am)