The compelling reason is that you are able to spend bitcoin directly. For you it may be a hassle because you don't want to ever touch your coin (evidently you don't own many). For some people, it's an opportunity to extract some value from their profits.
If that is compelling then you are easily compelled. I would be more than happy to place a bet regarding who of us holds more BTC
I'm not a betting man... and mine wasn't a challenge, just a supposition. If you do own many bitcoin (say, more than 30% of your net worth), then the more usual thing to do is to export a portion of your profits--even small--to other forms of store. Most of my BTC purchases have been like that, some gold/silver, some magic, some other stuff... just in order to ensure a portion of my gains is in a different form, suitable for different times.
in that case, the ability to spend bitcoin directly is compelling and costs less than using regular cash.