If "grittier feel" is the goal, yes, it's a feature.I would say that it's a feature of that transition, not a bug, if you're going for a grittier feel.
In this case, however, my goal was to keep monks, warlocks, and fighters from losing out on their short-rest recharges, without forcing me to plan adventures around giving them a 1-hour break. The "5 minutes, twice a day" solution achieves that goal with minimal disruption to the rest of the system.
Personally, I like the grittier feel and having to carefully husband one's resources. But I cut my teeth playing 2E wizards, throwing darts and hoarding my spells like gold. Most of my players were introduced to D&D in late 3E or later, and they are not fans of that style of play.