Lots of controls on userforms

I'm not really sure where to put this, forum wise, so I'll stick it here. I was just reading this thread http://www.excelforum.com/excel-prog...een-saved.html whete excel crashes when referencing a huge amount of controls on a page (I didn't know about the issue, but I don't find it particularly surprising), what I do find surprising is that the author alludes to this being a common problem amongst users, and there are follow up comments which appear to support this.

My question is why is this such a common problem? I can't actually ever foresee a need for 500!!! controls adding to a form at design time - it must be soul destroying to support and create. Does anyone actually have a real life example where this has been the only solution to a problem?