I see it all the time.  Managers have a block setting performance goals that don't have clear metrics.

A big key when it comes to setting performance goals—you want the goals to be measurable, but that doesn’t mean you’ll have metrics for every performance goal you set. In broad terms, your performance goals are going to be measured one of two ways:

1. Quantitatively – means there’s a metric or a statistic you can pull from somewhere to measure your Team Member’s performance for the goal in question; or
2. Qualitatively – means there’s no metric or statistic you can pull from, so you’re left with the difficult position of measuring performance via “manager observation”.

Which I actually prefer, because when it's done well, it results in better coaching conversations.

Just because you can’t measure a goal via a metric or statistic doesn’t mean you can’t include the goal in your goal setting for the position in question. What it does mean is that you have to be very clear about what successful performance looks like for that goal. Instead of a metric or statistical goal, you’re going to be describing the behaviors that lead to successful performance, then committing to have candid feedback sessions about what you’ve seen in the review period.

Remember—the manager should be the expert. Walk the walk and spend the time, and you can bring subjective measures into performance goal setting. However, if you don’t spend the time setting expectations about what success looks like with the “manager observation” areas, you’re going to have a mess on your hands.

Of course, manager observation takes work - both when you set goals and are tring to describe what success looks like, but also when you are giving feedback and contrasting what you saw vs what was expected.

Metrics are the crutch of managers who don't like to tell people they could do more.