I generally keep lower stocking levels but for a differant reason. Safety. During a power failure a heavilly stocked tank will crash and kill off the fish MUCH quicker. That said... a lot of us have back up plans in place for just those situations. Even in nature...a lot of fish species will chose to live in large, some might say crowded, groups rather than off on their own.
If you want to be really honest about it a little 3" pleco in the wild has MILES of clean water to live in. You could use that as an argument for not keeping any fish at all.
Your fish are healthy, happy, well fed and in no danger from wild preditors such as birds snakes monitors...ect. Ignore that nonsence it's just the old Ford/Chevy/Dodge debate in another form.
BY the way...I have a 5500 gallon tank...do you think I could squeeze in a secound Beta? J/K