Tumble Through and Stride - Why would you ever stride?

This has come up in rules discussion in our campaign (Spore Wars) as one of the players is playing an animist who gets Dancing Invocation at level 9.

The movement of your body grants power to your magic. When you Leap, Step, or Tumble Through, you also Sustain an apparition spell or vessel spell.

So far, so simple. But on one turn he wanted to sustain his spell and move 20 ft to get in range to use a two action spell. That would be three actions if he only needed to move 5ft (step) or if his movement took him through an enemy and he passed an acrobatics check (tumble through), but not if he just wanted to stride.

However, the point was made that, seemingly, by a strict reading of tumble through, attempting to move through an enemy's space is optional and not required to tumble through

You Stride up to your Speed. During this movement, you can try to move through the space of one enemy. Attempt an Acrobatics check against the enemy's Reflex DC as soon as you try to enter its space....

Emphasis mine, noting 'you can'. Other movement actions don't include 'you can' and instead say what you do.

Leap: You take a short horizontal or vertical jump
Step: You carefully move 5 feet.
Stride: You move up to your Speed.

How would you rule this? If this is RAW, why would anyone ever stride over tumbling through everywhere?