Ranger: "All right everyone, we've reached the dark cave of Morgordorgorath. We need to fetch the treasure of Kliy'shae from its lowest level. But we're severely outnumbered by the horrors lurking underneath. We need a plan."
Thief: "Let us steal silently in, taking the shadows to remain out of sight. Maybe we'll get attacked once or twice, but we can use the element of surprise."
Ranger: "Not bad... but it seems a bit too 'plain'."
Wizard: "I will use one of my blinding spells to stun the enemy!"
Ranger: "Maybe, but it feels like it's missing something..."
Brain-dead Fighter: "Let's just wander in circles within the same 5-square radius and wait for enemies to attack us! Then we'll just use 80 healing potions until we're strong enough to just plow through everything. "
All in unison: "BRILLIANT!"
AND LO, A TRULY EPIC ADVENTURE WAS HAD.
I liked this for one reason, which also coincides with what light has also said: The real issue, as shown in the quote above, is forced grinding.
I've played games with RE and TE that do the same as above, forcing you to repeat rooms over and over again and wander aimlessly just to grind against monsters in order to have a chance against the later areas of the dungeon. Regardless of the battle system you use, the player should be able to walk through the entire dungeon and be at a decent level to take on the boss, without being severely under-leveled, assuming they fought everything they met on their course through the dungeon.
The enemies you fight should also have given you enough gold to be able to purchase a few supplies and some of the needed equipment, allowing players to decide which is more important. If the player wishes to buy even more supplies or armor, or wishes to level up even more, that's their perogative, but it shouldn't be required.
For TE, I recommend no more than 2 enemies for every 17x13 area of space. For RE, I recommend no less than 50-75 steps for every encounter in smaller dungeons, and no less than 75-100 steps for larger dungeons. Exceptions might be made for extremely small areas, like a 17x13 map, in which case you might consider lowering the steps for each encounter to around 35 steps, only because the player won't be in the area for longer than a moment.
Regardless if TE or RE, no enemies should be present in puzzle-based rooms. There is nothing more frustrating than breaking my chain of thought in solving a complicated puzzle by enduring agonizing torture at the hands of a mod squad.
Finally, think of ways to spruce up encounters on the field. For RE, you can create items that turn off encounters temporarily (a repel system), or have lower level encounters turned off when the player reaches a certain level; after all, if I'm forced to go back through a level 1 cave when I'm at level 10, the last I want is to find level 1 enemies that won't put a dent in my needed EXP gain. For TE, you have even more control, since you can alter the enemies, randomize them with variables, use switches to change them up, and even create on field events that allows the player to engage the enemies in ways that can turn the table of battle. The most common is, if you surprise the enemy first, you will get a pre-emptive attack. But you can also create on field abilities that may allow you to stun or slow the enemy down, or other things as well.
But regardless of the encounter, the player should never have to "wander in circles within the same 5-square radius and wait for enemies to attack".