Even if those offended are just ignorant about the word "Hinayana", why use it? Why use a word thought by some to be offensive even if the meaning isn't meant to be offensive?

There is no other word that can be used? Would using another word (or phrase) be compassionate towards those who might get offended by it's use even if the intent wasn't to offend or provoke?

Is "Hinayana" so sacred, useful and descriptive that it must be used even when talking to an audience that likely has people in it who would be offended?
In my very first encounters with Buddhism I've always thought, that this is simply the distinguition between "maha" and "hina" in a sense of a larger fraction and a smaller fraction of the sangha in the first larger schism after the second(?) council. An example already known to me was the pair of nouns "Men-shewiki" (smaller fraction) and "Bol-shewiki" (larger fraction) of the communist movement at the early time of Lenin, when the two fractions separated due to different view of things and of how to proceed.
So also the basic term "maha-sanghika" came to me, as "the larger fraction" of the sangha, and I thought, "maha-yana" and "hina-yana" was simply derived from that (physical) comparision of size (the "vehicle of the larger/ smaller fraction").
But with irritating frequency I heard of disgust of buddhists connected with the term "hinayana" - and I'd seen one time in an online discussion someone telling, that "hina" does not simply mean "small(er)" but has a derogatory, diffamating tone.
It seems difficult to find an entry in an actual dictionary (online, don't have a Pali/Sanskrit dictionary at my own), but I found this in a yoga-wiki:              

http://wiki.yoga-vidya.de/Hina                         


  Hina (Sanskrit: hina adj. u. n.) ist das PPP der Sanskrit Verbalwurzel
  (Dhatu) ha und bedeutet: verlassen, zurückgelassen; mangelhaft,
  fehlend, klein, gering, schwach; kleiner, weniger wertvoll; Mangel,
  das Fehlen.
  (I try to translate but may miss the tone of valuation: "... lost, left behind; buggy, missing, small, low, weak; smaller, less valuable; the lack, the missing")


... while I still do not know the opposite term of "maha" simply with the meaning "small" without a social/valuating tone.            

(In principle) I still cannot understand how such a connoted term as "hina-yana" could have at all been born in the sangha of the followers of the Buddha - possibly coined by members simply of "the larger fraction" ("maha-sanghika") even when they thought themselves (and maybe correctly) as practioners of a "wider concept" ...            

The disgust of Theravadins seems to me understandable, if I imagine of calling one path/"vehicle" the "omnibus" (mahayana) and the other one the "Bobby car" ("hinayana") using english language - and even to insist on such an implicite valuation in face of the concern with this, which was expressed openly many times and also long times.                

A funny/joking example of the tricky relation of ours to the terms "large" and "small" stems from the former socialistic german republic, when the ideal(!) of smallness (in the realms of electronical devices) could not be met as perfect as in "the west", and the people ironically trumpeted: "we have the largest microprocessors of the world!".           

So in focusing more on the answering of your question - surely it should be advised to look at common examples, where the "smaller" is the "finer":       


being more focused        
having more concentration,         
being free of a bunch of litter (and -for instance- of fetters)


and -just for the mental exercise of emanicpation from the connotations of "greater" and "less" - one can try to find then actual terms for the advantages-of-the-smaller to get rid of any feeling of being-pissed, of confrontation or even of revenge or of any unkind emotion which might come up when feeling bullied by the term "hina-yana"....