lame and cool r subjective
I dunno, I think Doublelift identifies the specific factors he's reacting to when he calls something lame.
Riot's explicit goal with this patch was to buff ADCs that rely on auto attacks (Tristana is the classic example) compared to ADCs that rely on abilities (Lucian is the classic example). Doublelift's contention is that ability-based ADCs are more interesting to play and have a higher skill cap, so this change makes the game less interesting and reduces the value of skillful play as ADC, which is obviously pretty relevant to him. You might disagree, but I think it's more detailed than "lame."
The other two main points he made are that ADCs take longer to become relevant, which is probably true because the overall item changes probably do add up to ADC item nerfs, and that hyper carries are frustrating design in general.
Basically, against Jax/Tristana/maybe Nasus, the counterplay is 1) bully them hard in lane, and then 2) win the game before they catch up. Since 2) is already the goal, this basically means that champs like this put a clock on the game.
Now, I don't think this argument holds up given the lousy performance of hyper carries in LCS this season, but it is an argument!