Why lefesteal Thanatos is better than CDR Thanatos

A couple weeks ago, I got unwillingly thrown into the jungle role. I'm usually okay with playing jungle, I just wanted to go solo that game. So, I decided to play an easy jungler; naturally I picked Thanatos.
About 15 minutes into my game though, the 1-7 Ares decided to start criticizing my build, saying I had no idea what I was doing, and that CDR is the way to go on Thanatos. I laughed him off, but this made me realize how little people actually understand Thanatos, or how to build him.

There are a couple reason why lifesteal > CDR on Thanatos.
1. Most people who believe that CDR is the way to go, is because of his ultimate. Their reasoning is that the more his ultimate is off cooldown, the more often he can execute enemies! While this is true, without lifesteal, Thanatos gets steamrolled in fights. If you don't have enough lifesteal, you will die immediately after using your ultimate. Then, you are left having to build defense on him so you can escape after using it. Now you have completely transformed Thanatos into a CDR bruiser/tank, and he is no longer capable of boxing with enemies, and can't play his role as an assassin.
2. Thanatos is an assassin, and is played best as a such. The whole point of assassins is to be able to melt single targets very quickly, but without lifesteal, Thanatos can do very little against many gods in close quarters. An ADC can easily kill Thanatos in a 1v1, given the ADC has lifesteal, mages can typically burst him down, and tanks/bruisers aren't an assassin's target. With lifesteal, he can easily outlast and outdamage other gods, sometimes even in 2v1 situations.

Thanatos is the only god that I build 2-3 lifesteal items on. If you build him with CDR, try him with lifesteal, so you can realize your mistake.

This post sounds rather arrogant.

I go for both. Warrior Tabi, Devo Gloves, Jotunn's Wrath, Malice, Deathbringer. I sometimes get Eye of Retaliation as my last, sometimes I get Hydra's Lament. Both work.

Also, you didn't give a poll option for both.

My idea, is why not both. This option is not on the poll.

CDR boots and Jotunn's Wrath is enough for that. The CDR boots sacrifices penetration, which Jotunn's alone makes up for, PLUS having CDR. You then have 4 items to build however much lifesteal you want. You could legitimately go Qin's Sais, Bloodforge, Deathbringer, and Malice, and still be ok. Even swap something out with a Heartseeker if desired.

Maxing CDR will get his Scent of Death down to a 7.8s CD on a 6 second duration, which is a fairly decent uptime, and this buff gives even MORE penetration, plus speed. This makes him a ridiculous roamer and threat in teamfights, since he can't be slowed. His scythe also lowers to 7.8s, and his soul reap comes down to 9.

This will allow him to actually get off multiple rotations in a fight, while still allowing him to auto attack in between with the penetration and flexibility in the build.

Since you didn't list it, I won't vote on this poll.

Ah! My bad, I didn't think about both for the poll.
I still prefer Warrior Tabi, Crits, and lifesteal though.