This is a classic example of bad/wrong/fun debates in our hobby.
Not only is this a simple thing to house-rule; it works very well as written in every edition that uses it and works just as well if house ruled.
The argument often occurs with someone stating that 'movement rates are too slow'. That it isn't 'realistic enough'. That it is so unrealistic that it destroys verisimilitude and they can't play if torches are going to be used up that fast.
This results in discussions that endlessly go back and forth trying to prove what's real. These are generally unproductive to engage in.
Here are some things that are often overlooked.
Movement is a game construct. You can move 3, 6, 9 or 12 10' x 10' "squares" a "turn". The differences in these rates of exploration means that the costs (in torches, ground covered, time spent) are significant. The fact that the choice of how encumbered you are has significant consequences makes the choice an interesting one. Choosing to change the exploration rates makes this choice meaningless, meaning there are fewer costs to being weighed down with armor or treasure.
Eliminating interesting choices certainly changes the focus of the game, especially since many of the choices involved are important ones for low level characters. There are much fewer costs to wearing heavy armor and torches and other equipment become much less encumbering if movement is sped up.
Now the real world movement rates are very slow. Several people by themselves have done 'tests' where they map their environment or attempt to cautiously move around in these environments. In every case they say, 'I am able to walk so much faster then the listed rate'. They then reach the conclusion that the listed rate is wrong. In every single case none of the following is considered.
The environment is cramped and pitch black. The ground is uneven in the best case. The light is torchlight. Mapping is done with either parchment and charcoal or an ink pen. There are no hash marks or clear markers to indicate distance, it must be measured. Groups range in size from 4 to 12. Many are uneducated hirelings. Many are wearing metal armor and carrying heavy gear. Movement must be coordinated and silent. The rate is an abstraction, looking around corners, stopping to listen (and having to get everyone silent first) and quiet hurried discussion about what to do make up for the time spent moving slightly faster down an open corridor.
When you look at real world examples of these things the movement rate is much more realistic. Getting people in line and moving orderly is time consuming. Exploration of caves tends to take much longer (with modern equipment) then people assume, and we know they aren't trapped, filled with demons and monsters, and actively inimical to your survival.
Play how you want, but know the rules and the reasons for them before you break them.