Would any of you say that you have a 'fraught' quality to some of your emotional/primary Fi processing? I have a theory that those with dominant Fi may have more of a 'neutral' emotional slate, or have a more difficult time accessing or analyzing their emotional state in the absence of strong emotion. I myself will usually not respond in an 'emotional' way unless someone is challenging one of my values.
Another way which Fi doms may describe themselves as emotionless is in the context of their personal relationships. Fi doesn't always lend itself to social convention or to facile emotional interfacing, and this may cause fractures in the relationships of some Fi dominant people.
Of course, Enneagram may have some effect on whether any of this applies to you - I can imagine this might be more accurate to types 5, 6, 9, possibly 1, and certain 4s (who may also at times consider themselves emotionless when not experiencing strong feelings).