Yes.. I know this has been asked many times before, but the argument tends to go both ways. From what I can gather, those defending the inability to take a 5' step during a whirlwind attack do so because it's a SINGLE attack (spinning around) to hit your targets.
I'd like to counter that logic with a scenario.
......
..XX..
.XOA..
.AAX..
In this scenario, X is the enemy and A is an ally. By using the logic of "You swing your weapon around you and hit everyone in a single attack, you're going to be doing a roller coaster of a swing to avoid hitting your allies.
If you then choose the side against this argument, you then see the character as taking a separate swing against each enemy and thus avoid the whole roller coaster situation and would thus allow you a 5' step between two of the attacks. (this is my standing but would like some feedback)
I think the general flat solution is that while you can take a 5' step during a whirlwind, your potential *targets* are set at the beginning of the whirlwind and do not increase for stepping closer to someone else.
Love Whirlwind, and it can certainly be flavored in a lot of different ways, but no need to add this complication to its utility.