Then I must question your usage of Chesnaught in those scenarios. The only thing that I can possibly agree with is your point on Talonflame with Dugtrio. Given the team make-up, I find it rather difficult to believe that you were using him as the physical tank that he is, without being able to predict the obvious Crobat or Talonflame switch-in. Were you switching in on those as they came in? Were they switching in as you were setting up Spikes? Did you not have Stealth Rocks up on the field, which a few of his partners tend to carry?
If you're just throwing him in your party for the sole reason of setting up Spikes, then you're going to have to consider why you should use him instead of every other Spiker, and it is possible that he simply didn't fit into your team. Considering the success that is reported on this thread by other users, that may as well be the case. However, if you are using him to not only set up Spikes, but check & tank specific threats, which he is able to do better than not only (certain) other Spikers (which to be fair, isn't really their main job), but with an actual healing move that Forretress and Ferrothorn would kill for. Forretress has Volt Switch. Good for him, and he uses it well (most certainly not as a main offensive option - it is rather weak), however he also has a host of issues himself. And any other spinner can accomplish what you've just mentioned; not one of the hazard setters can reliably stop a spinner from doing their job. If you're that worried about Talonflame, by all means, give him Stone Edge over Roar/Leech Seed.
The issues you've laid out is what keeps him from being an OU staple. His pluses are what make him very much OU viable, which is the general consensus in this thread.
And...I mentioned Greninja because you did, for whatever reason.
Sometimes when your opponent puts offensive pressure on you you fail to find time to set up any hazards. Or use Synthesis. That's one of the biggest downfalls of any defensive mon.
Chesnaught just can't find time to do anything against a team with an Aegislash, Greninja, or Talonflame. Considering that those three mons, plus other stuff that kills him like Gliscor, Skarmory, Crobat, etc. are used on like 80% of all OU teams, I found it quite hard to find time to do anything.
Of course I used SR whenever possible. But if the opponent can kill my SR setter with their lead, if my opponent gets a free switchin to a troublesom set-up sweeper if I use SR, if whatever, then I couldn't set up SR. With Chesnaught, these opportunities are even more common--even with SR up you can't give free switchins to Aegislash. Or Skarmory. Or Gliscor. I had even lost to a fair number of Excadrills, because they spin as Chesnaught comes in, then switch into their Talonflame or whatever. You
cannot stop Excadrill from Spinning unless you are already on the field, in which case Excadrill is not coming in. I actually found myself having to use Gourgeist to stop Excadrill from Spinning my Spikes, and wasn't Chesnaught supposed to beat Excadrill?
I cited Greninja because Chesnaught is pressured and beaten and forced out by the top three mons in OU, one of which is Greninja. Against those 30% of teams with Greninja you have to randomly throw out Hammer Arms in fear of Greninja, which gives you even less opportunities to Spike.
What forces out Chesnaught easily in upper OU:
-Aegislash
-Greninja (can't switch in on Hammer Arm)
-Talonflame (can't switch in on Stone Edge)
-Gengar (If running Hidden Power or Icy Wind)
-Goodra (Can't take too many Hammer Arms)
-Azumarill
-Noivern (can't switch in on Stone Edge)
-Alakazam (can't switch in)
-Dragonite (can't switch in on Stone Edge+SR)
-Gliscor
-Charizard (can't switch in on Stone Edge)
-Trevenant
-Sylveon
-Gyarados (can't take many Stone Edges)
That's just the top 25 of OU.
What Chesnaught forces out/beats:
-Gengar without Taunt, Icy Wind, and Hidden Power. Only damages Gengars with Stone Edge.
-Ferrothorn
-Tyranitar
-Excadrill
-Physical non-Mega Lucario
-Smeargle (lol why do people use this thing)
Toss-ups:
-Scizor
-Klefki
-Garchomp
-Rotom-W (dat Wisp)
-Mega Lucario or Special Lucario
-Kangaskhan
-Malamar (why do people use this thing)
So...yeah. In terms of the top OU meta, there's a bunch of stuff that beats Chesnaught, so it's switching out of all of them. Therefore, it'll be hard-pressed to find much time. If he uses Stone Edge he loses even harder to stuff like Aegislash and bulky/Mega Gyarados, but if he doesn't then there's a bunch of more stuff that beats him. Not to mention,
you have to hit them on the switch since they are faster than you. And if you mispredict, you just revealed your ace in the hole. That's why he is currently hard to use in OU. Note that I never said unviable.