The reason I prefer “work-life integration” is that if people are always striving for a mythical balance, they often feel stressed because they're not achieving that balance. You're absolutely right that you need to look at how efficient the process of Parliament is and how it helps members meet their responsibilities.
If people are passionate about what they're doing and they really care, they're not always concerned that they spend an extra hour here one day and less here the next. I think that's part of what we mean by work-life integration. It's not always possible—in fact it's rarely possible—in the kind of roles that MPs play or the kind of roles that I've played over the years to have that perfect balance. It's more whether we feel satisfied with what's going on or feel supported in being able to take on responsibilities.
That integration could work differently.
You've talked about family events. Sometimes you go to family events and you don't spend the time at the workplace, and that should be just fine, because that's the kind of thing we need when we're talking about “integration” and not necessarily “balance”. I agree with you.