Portal Abilities can be exceptionally strong when used correctly. They can be a great benefit to the team or other players in certain situations.
Do you think more classes should have the ability to create portals that allies can travel through?
With some exceptions of course.
For example, maybe one in each armor weight class. They can be steered to the least played classes (Reveannt and Engineer) and each are unique in their own rite and be tied to an elite spec.
Revenant - Some kind of mistwalker spec where the user can create a portal that is only one way. Perhaps users gain stability and/or protection upon exit.
Engineer - Has to build each side of the portal using some kind of special mechanic (like picking up scrap during battles). The portals can be destroyed, but also repaired using toolkit.
Each has the same limited uses as the last.