Thus, I see practical/impractical to be more limiting than whether or not an idea is actually entirely coherent, from a purely logical standpoint. And again, Ti never usually stifles an INTP's thoughts. Ideas are bouncing around and Ti is trying to control them, but those ideas will be considered and played with as long as they are coherent, even if they don't actually apply to the real world. Hence, INTP's enjoy thinking in and of itself, and enjoy thoughts even if they may not be practical or applicable. INTP's appreciate beautiful constructs of thought
, even if they aren't worth anything in a practical sense. INTJ's only enjoy thinking with a purpose that has clearly defined ends, i.e. — something that will actually be worth the effort and pay off in the end. INTJ's don't like armchair philosophizing as much as INTP's. To me, this is more narrow-minded.
Considering only ideas that are shown to work is not open-minded — it's narrow and limited to what is practical and applicable to the real world. Boundless amounts of possibilities are bubbling around in the world beyond what we may 'think' is workable or practical. ENTP's and INTP's show this often. We're more open to what may be beyond current comprehension. Hence, INTJ's are limited to what 'seems' practical in the current, according to what we know scientifically. NTP's may look beyond our current understanding when seeking possibilities, and this difference is crucial. Thus, INTJ's might be open-minded, to an extent, but nowhere nearly as open as ENTP's and INTP's. They seem to have a natural epistemological barrier upon which they tend to rely. They don't enjoy going beyond empirical boundaries. So no, INTJ's aren't open-minded in the way INTP's are, and I wouldn't really call their sense of possibilities "open," per se. You're really reaching here.
And the notion that Te appears ruthless at times is the tip of the iceberg — it's often entirely tyrannical and brutish.