From my point of view, it would be the last line of defence. 99% of problems could be sorted out with a forced landing, as even a bad one will still be a better option than a near vertical landing albeit somewhat cushioned...
Main things that would make it a no-brainer to pull the handle would be:
1) Inflight structural failure
2) Mid-air collision
3) unrecoverable spin ( but again, you have to be trying hard to spin accidently if you have passed your PPL)
4) No viable forced landing option.
Can never really see an extra option being a bad thing, as long as the user is aware that it is not a get out of jail free card.
In some ways I find that the more dangerous the activity, the more careful people are, hence aviation safty is very impressive, compared to road users who are molly-coddled by cars with a vast array of "idiot behind the wheel" driver aids such as: ABS/ traction control, stability control, airbags etc etc , and become complacent of (very very)poor driving, hence why road accidents are so common, 95% of the time a modern car covers up peoples appaling driving skills.