Tough love is bullshit and what you did was awful. You could have explained how his complaining, coupled with inaction, made you feel. You could have cut ties. You could have calmly offered solutions again. You could have just listened.
What you don't do is berate a friend for 40 minutes on how much of a loser they are and how they're to blame for everything. Jfc this is an infuriating thread.
I do not think tough love is bullshit... or perhaps my idea of it is different or maybe it is a bullshit phrase that it is used too often by people who think "THEY'RE KEEPING IT REAL."
Honesty is important in close friendship, and so is being able to show our true selves (being vulnerable). Sometimes being able to shut the fuck up and listen to someone helps too. I learned the hard way you do not help people by simply listening and telling them how to fix their lives in most cases. Because honestly, we are all dealing with our own shit, and sometimes the best we can do is show up when needed and be supportive.
I do not think bringing up shit from the past and throwing it in someones face is the proper way to push someone towards growth. If anything, it comes off as pretty judgmental and does not allow them to look forward. And failure... lol really? If he is still working, still breathing, still living... he is the opposite of that. He is seeing that he is not getting anywhere which is good, but to put him down because of it, why? Why not at least preface with something like, "I care... I really care for you bud, but you really need to get it together." Why not ask him what it is he wants to do, what is that he loves, shit, instead of having him compare himself to his brother ask him to compare himself to his favorite fictional or non-fictional figure. You can cheer someone up while being brutally honest and still taking their feelings into account... it takes some emotional intelligence and empathy/sympathy but it's not impossible. You do not have to choose between honesty and their feelings...
Success demands failure, to label him as that imo robs him of the mindset required to grow and get better. I think OP had good intentions, but kind of dropped the ball here. It sounds more like he needs someone to understand him more than anything.