i'm with josh on this one... you guys view lifting vs cardio/conditioning as an entirely "either/or" thing. it is quite possible to gain strength and size at the same time as improving your conditioning. restricting rest periods, supersetting, tabatas, 20-reppers, circuits or cardio finishers are simple and contextually appropriate for everyone. doing these things is not going to cause you to spontaneously combust, kill all gainz and break down all muscle tissue. these are not mutually exclusive concepts.
dat first unit of marginal utility i've gained from building up my conditioning is well worth it. im able to maintain the same output of strength for longer, do more more volume with more intensity with less rest, etc; the benefits to any lifter are beyond obvious here. it is a piss-poor excuse to dismiss the benefits of GPP and conditioning on account of ***gainz*** because one could only possibly benefit from a reasonable and appropriate amount of conditioning thrown in.
no one is saying you have to do everything in a circuit and rip out 7 minutes of burpees. "conditioning" is not exclusively bodyweight circuits. it is not an overcomplication, and its a logical fallacy to assume this very broad concept is something diametrically opposed to the goals of anyone who wants to get big and strong. i don't buy the functional strength business outside of being a generally useful person who doesn't get sick or injured easily and can pick up things and not get winded going up stairs. this also has nothing to do with some ideological condemnation of the irony of someone dedicating themselves to lifting but can't do cardio. from a purely performance, aesthetic, and strength standpoint, EVERYONE itt would benefit from working in reasonable and appropriate conditioning conducive to their goals. everyone. greater conditioning = doing more work in less time. being more efficient is not going to jack up your grocery bill to an unreasonable amount and prevent you from putting on size.
i think its a poor excuse for anyone remotely interested in lifting or fitness to disregard it on account of gainzzz. for the vast majority, its definitely a "why not" versus "why." as for the not working hard thing - are people afraid of hard work? is it somehow superior to not have a "hard workout?" i don't confuse feeling like i've been kicked in the sack with automatic gains, but taking things easy for the sake of taking things easy is pretty lame and i have to question the validity of something as devoid of quantitative benefit as "LOL working hard is for noobs, youre wasting time."
key words here are reasonable and appropriate. for the average gymrat wanting to get big and strong, no reason not to work with supersets and restricted rest periods and perhaps a circuit or two. for a guy two weeks out from a comp, it would be a pretty bad idea to do 15 minute HIIT sessions. to dismiss it outright is a cop-out, and i question the ability to harden the fuck up of those who do.