Th Cheapening of the Fantastic
I view it as a cheapening of the fantastic, magic becoming commonplace and therefore desensitizing people to how wondrous it's supposed to be.
All the time, I see threads with people complaining about how magic doesn't "feel magical" anymore, and they don't understand why. And yet they then go on to describe how their characters have 7 magic swords and 10 magic wands and 3 pairs of magic boots and 2 pairs of magic underpants. Too many people don't seem to realize that when EVERYTHING is magical, magic becomes mundane and ordinary and BORING.
At some point, if we're letting things become so detached from reality, we may as well set the standard height of humans at 7 feet, and set average human strength as able to bench press 400 pounds.
I believe that the game should be rooted in reality, and things that aren't supposed to be inherently fantastic or magical should be as close to real life as possible. Without a firm grounding in reality, the fantastic elements of stories and games are cheapened. What makes a dragon special if you see ten every day? What makes magic special if you see 4 spells cast before breakfast, and eat that breakfast off of a magically glowing plate? If you want the fantastic elements of a story (or whatever) to be seen as adequately fantastic or magical, you really need to have the majority and base elements of the world be mundane and rooted in reality, or EVERYTHING will seem fantastic, and by extension, eventually NOTHING will seem fantastic anymore, because the fantastic becomes standard and mundane. If magic become common then it is ordinary.
I also know quite a few people who simply wouldn't believe me that historic "longswords" (or arming swords, historic "longswords" would be bastard swords in D&D terms) were only about 3 feet long and weighed around 2-3 pounds, and two-handed swords were only about 5 feet long and didn't weight more than about 7 pounds, because they'd become so used to the ridiculously exaggerated depictions in D&D and videogames that they just couldn't conceive that things weren't like that in real life. I showed them actual photographs of real, historic "longswords" and they dismissed them as shortswords or rapiers! In fact, MOST D&D players believe this stuff, to the point that "D&D player" has become something of an insult in some forums that discuss historic swords, because of the horribly distorted image of swords that most D&D players have.
Now, as for games where healing takes a more realistic, longer time for characters to heal, well, in my gaming group, any time one character was laid up and needed a large amount of time to heal, such as in some of our AD&D 1E games without a Cleric, the other players had the common courtesy to wait for him to heal, rather than go right back out adventuring without their wounded companion (and thus leaving me as his player twiddling my thumbs.)
If I was playing with a group that consistently left my character in the dust to go adventuring without him (and consequently leaving me as a player to sit around doing nothing) rather than simply have their characters "wait" for my character to heal up, (which would consist of everyone as players simply saying "we wait for him to heal up" and not taking any time away from the players at all) I would stop playing with them rather quickly. I would consider it to be extremely rude and selfish.
Now, if there was a time-sensitive issue that needed to be taken care of and the other characters just couldn't afford to wait for mine to heal because it would cause them to miss the window of opportunity to accomplish something important, then that's different. But if the other players simply wouldn't allow their characters to "waste time" on me (by waiting for my character to heal) just so they could get back to routine, non-time sensitive adventuring, then I would consider them to be extremely rude, inconsiderate people, and would quit playing with them rather quickly.