"%(name1)s %(name2)s"%{"name1":"ABC","name2":"DEF"}
"{name1} {name2}.format(name1="ABC",name2="DEF")
Even if Python never gained the .format() option, so #2 weren't an issue, you would still be stuck with #1, because '%' supported them as well.
As for logging, I pointed out two possible ways to address the problem. Personally, I don't log in performance critical loop since Python's function call overhead is so high. Testing now, you can see that 3/4ths of the overhead for logging a simple format statement is just in calling the logger:
% python3.3 -mtimeit -s 'import logging' 'logging.info'
10000000 loops, best of 3: 0.0525 usec per loop
% python3.3 -mtimeit -s 'import logging' 'logging.info("abc")'
1000000 loops, best of 3: 1.59 usec per loop
% python3.3 -mtimeit -s 'import logging' 'logging.info("abc %d %d %d", 1, 2, 3)'
1000000 loops, best of 3: 1.71 usec per loop
% python3.3 -mtimeit -s 'import logging' 'logging.info("abc %d %d %d"%(1, 2, 3))'
1000000 loops, best of 3: 1.64 usec per loop
% python3.3 -mtimeit -s 'import logging' 'logging.info("abc %d %d %d".format(1, 2, 3))'
1000000 loops, best of 3: 1.99 usec per loop
Is your objection based on a measured performance impact (eg, more complicated formats will be worse) or a theoretical evaluation?
Why? dunno... probably habit, sample code never showed it, mostly because it would be ridiculous. Why is it not ridiculous with {}? It is, though he would never agree.
I usually don't care about performance either, but the third example is easier to read and type. Looks just like a printf.
> There was a guy at work who insisted on using .format() for everything that soured me on it, sometimes even simple string concatenation
It sounds like you are soured on new-style .format() because someone else doesn't use it appropriately. You concluded that it's intrinsic to .format(), even though s%{} is even more verbose, because of what seems to be an idiosyncratic preferences of one person.
I empathize with your other arguments. I too am much more familiar with printf-style % arguments than the Python-specific .format() syntax, which still cause me to reach for the documentation. But I do not think that it's reasonable to complain about its verbosity.