I haven't ever heard of someone praising them. I have heard people enthused by the mystery of the order, and the various myths that have sprung up around it.

To compare them to terrorists is fallacious in the extreme, as well as anachronistic. They were an international organization, authorized by the pope to guard pilgrims on their way top the holy land. That they were a militant group does not equate them to terrorists, as they were not furthering their own goals, but were simply protecting what had already been conquered by the first crusaders (or attempting to reconquer, but that still falls within that job description).

They also became a sort of "proto-bank". Pilgrims would donate their belongings to the order, in exchange for a note of appraisal for what the items/land were worth. they could then exchange the note at any branch of the order. The production from the land they accrued, in addition to the belongings of deceased pilgrims made them incredibly rich.

They were also very secretive, with secret rituals and draconian rules, they drew suspicion like a magnet. That, and after living with the Muslims (often quite peaceably) for decades, they had picked up some eastern habits, they were eventually disbanded for heresy.

The charges were brought up by the king of France, Philip IV, who owed huge sums to the templars, and it is believed that his main goal was to destroy his debt while acquiring as much of their own wealth as he could, and the heresy was just a plausible excuse.

According to legend, while on his execution pyre, the grand-master of the order cursed the king, his torturer, and the pope, and that they all died within a year. Combine that with the fact that most of the order fled to ground, it's easy to see why there are so many myths and legends about them.