I love EMs. In fact, I'm just warming up to the more modern machines with all the bells and whistles and toys and blinking and buzzing and flashing lights. I'd much prefer a room full of chimes and bells (with some rock playing in the background) before I can take the cacophony of voices, music and sound effects coming from a bunch of more modern machines (can't hear the music over the din).
Firstly, I grew up with EMs - and I think that's a significant point. Just as younger folks who never knew a time without computers, DVR, internet, etc can't imagine or appreciate (the nostalgia of) a time without these technologies, I think EMs tend to be seen as old-timey.
Second is the actual technological differences between older and newer machines - particularly in the areas of power and mechanics. The heart of any pinball machine is power, and how that power can be transformed into kinetics. EM machines generally have less power available to move the ball around as quickly as more modern machines. This tends to give the impression they are slower machines - which, for some reason tends to give the impression that they are easier machines. The ramps, holes, subways, wireframes and other toys available on new machines simply add to the impression.
Lastly, I think the scoring of EMs compared to SS/DMD machines contributes to the impression. When the free game score of an EM can be achieved by simply launching the ball on a newer machine, its hard for younger players to relate to the score inflation - kinda like comparing 1976 dollar value to 2012 dollar value. For some its hard to compare a machine that gives 1 point for the same stand up target a newer machine will give 10K points when hit.
For these reasons I can fully see where there might not be an appreciation for EMs - particularly for those who grew up when EMs were already old.
The one fallacy I try to dispel is that EM machines are somehow easier because of all of the above. While it does take a different style of play to play an EM over a faster SS/DMD machine, the game design in relation to the technological differences makes them generally just as challenging (and fun) to play. I tend to find that playing my EMs before playing newer games improves my game on the newer machines. I guess the more patient style of play required for EMs carries over when I move to the newer tables.
While one might consider a '70s Ferrari as old and quaint compared to a more contemporary Ferrari, I would be just as happy driving either (and likely appreciate the older a bit more).
Of course, that just my opinion - YMMV