Better to have and not need, than need and not have.
Can't argue with that, but one has to make a value judgement here. Otherwise you might as well say that everyone in a light aircraft should always wear a 'chute 'just in case'. The logic is unarguable, but wouldn't it be a tad OTT?
So it comes down to:
Does aerobatting a Chippie (loops, rolls, stall turns only) increase the risk of loss of the aeroplane sufficiently to justify the cost and inconvienience of supplying, maintaining, and wearing 'chutes?
Also, I often carry an inexperienced passenger. Here's a moral dilemma for you: you get into an inadvertant spin that seems not to want to recover following standard recovery procedure. You throw open the canopy, and shout to your (well briefed) passsenger to jump. They freeze (I can almost guarantee they will). You still have 3000 feet, and it's still spinning. But there a few more things you know you could try to un-spin it.
Do you stay to try something to save the situation, or do you jump. If you jump, survive, and the passenger dies in the crash of the aeroplane, how will you feel?
SSD