SPD etc. are not just about aesthetics, far from it they are more about efficiency. Now because I want to be more efficient on my bike does not mean I am following a flock.
Those pedals still do not belong on that bike!
I knew you'd come back with efficiency and no-one is accusing you of following a flock - or is there something about wear and use what you like that you find hard to comprehend?
But shall we look at this efficiency bit, for starters the efficiency you refer to is only when on the bike. There are a lot of trips taken by bike where the efficiency calculation would range well beyond just the time in the saddle. Then there are the actual realworld gains, how do you calculate those, do you factor in all the variables? Or are you just making sweeping assumptions and generalisations? Is your final fall back position one of 'the pros do it so it must be right'? People tell you all sorts of things in sports and manufacturers make all sorts of claims about potential improvements equipment can provide. For most hobbyists, which covers most participants, they lack the natural ability, desire/dedication to improve or the fitness levels required to extract the gains that equipment purports to offer.
I'm pretty certain that you lack the required knowledge of the person that rides the bike in the OP to make any detailed efficiency calculation. So we're just left with...well....not very much other than that you have a very close minded view of how others should indulge their hobby.