Hirelings & Henchmen: My Players Hate Them!

OK, "Hate" may be hyperbole, but my two players have never once used a "hired sword" in all the times we've gamed.  The reason for this is simple: they don't want to split the XP and GP with them, and I think they just prefer the smaller party dynamic.  And they know that I will normally design adventures for a duo of PCs - since they like to run one character each.  So these past couple years I've carefully scaled my dungeons to make them challenging yet "beatable" for a smartly played party of two.

However, it can be much more fun to put in powerful encounters from time to time.  So I've suggested, cajoled, and tried to convince them that taking hirelings and henchmen will open up a whole new world of possibilities.  But to no avail. 

I suppose I could fundamentally change my adventure designs and make things tougher - perhaps too challenging for the duo.  They would then have no choice but to take hirelings.  But I haven't gone that route because I still enjoy running the game for two and they do not want to use hirelings.  In short, they dislike using hirelings much more than I dislike designing a dungeon for two.

My players don't mind hiring a specialist, such as a sage or a high level cleric.  But these are for one-shot requests like raise dead spells or magical research.  They aren't invited to the dungeon delve.

What has been your experience with henchmen and hirelings?  Do you like to use them as a player?  Why?  Does your referee create difficult enough adventures that you are compelled to take hirelings?  For the DM's out there, does it matter to you whether your players use these resources?  Do you design your adventures so that the extra help is needed?

The reasons I'd like to see them use these hirelings is because (1) I can design much tougher encounters and traps, and (2) it just seems like the way that D&D was put together.  An entire stat (CHA) becomes much more useful if hirelings are used.  Many pages are devoted to this topic in the old school rulebooks.  So it MUST have been an important part of the game to Gygax, et al.

Just wondering what you all think.