The points aren't what I disagree with, it's the attitude that his characters should be buffed just because he plays them and because he wants to win, and anyone who doesn't understand that is obviously not a competitive player. Fine, maybe the characters suck. Adapt and pick someone else. He's not entitled to have his favorite character be top tier just because he says so.
I won't deny your opinion, but that opinion is separate from the topic at hand and should be taken to the proper area for further discussion if any should be necessary. He likes characters, they got nerfed, he isn't happy. That's common, it happens all the time. He calls for buffs, and he isn't saying "IF YOU DON'T AGREE DS NEEDS TEH BUFFZ UR STOOPID SCRUB CASUAL".
He is saying people denying the harm the nerf did and disregarding Deathstroke's need for a buffing to make him a choice worth choosing over the idea of "oh just adapt" are not looking at it with the proper mindset. He wants to win, yes. He wants to play his favorite character and win with him. Sure, who doesn't? Saying that he is wrong for wanting buffs after an admittedly harsh nerf so his character has a reason to stand out as a choice over other options is ludicrous.
He had a solid character who is considerably less solid after a nerf brought about by a base of players whom likely won't stick with the game as long as people who will be forced to deal with the nerf will. I like Deathstroke, I feel he is solid but I can no longer deny M2Dave's ideal that he is not a viable choice.
People make the mistake of thinking a "viable choice" is the same is "general viability". Sure, yes, Deathstroke is viable. By all means, he can still win and still does. However, that doesn't make him a viable choice when theres other characters whom have better options that would provide better odds of victory. You can pick him if you want, but it isn't going to be the best choice. When it comes down to who wins and loses, "viability" is paper thin and only a clutch few are the true "viable choices" while others are simply "choices whom are viable".
Theres a difference between "Track Star" and "track runner". They can both finish the race, but one is more likely to win than the other. That's not to say you can't root for the track runner, sure he wins some races, but when you are putting money on it then it becomes a different matter entirely.