Yes, it's counter-intuitive and generally awful for an action game, not to mention that OOO has only completely unjustifiably implemented it for a few things. There's no reason to have it on some weapons, while not implementing it for the most OP ones like DR, Blitz, and Brandishes.

Them tinks are ruining all the fun in using da torts gun charge D;

Placing the Shocking salt bomb just in the right spot of the JK battle should be highly rewarding instead he gets a little over a 3rd of the damage he would take due to invinciticks, yep spamming DR is far more rewarding.

Also we don't get invinciticks from certain enemies,

Alpha wolvers (3 bites)
Battlepod lasers (dear glob)
Roarmulus lasers (ditto)
Arkus orbs
Gremlin Demo
Deadnaught charges (hits multiple times if you're unlucky)
Scarabs and Glop drops (wth guys)
Wheel Launcher and Shankle (as if the knockback from the launcher wasn't bad enough in a fire infested citadel)
Harvester (totally OP gaze that probably could have invinciticks added for easy but not intermediate or elite)

Note: I don't know the other difficulty names because I never play them

They serve no purpose other than to waste time, hiss.

many of the items that cause the "tinks" do damage at a much lower rate than Dark Retribution or Blitz, as stated above.

Paintool brings up a neat point. But i have have a better theory.

Conspiracy Theory:

"Illuminati made it"
----------------------------------------------------------------------------------------

Burn the evidence.

Remember those days when something went wrong and all the invincibility frames turned off? Those were the days (in lockdown) And anything that left a pool of shock permalocked you. On a side note: if they'll ever turn off invincibility frames and shorten the fuse time of shards (and well, fix shards not appearing) I won't need any other weapons anymore, they will be just too good.
I believe making the tortoguns have invinci-ticks is to reduce randomness. All the shards can potentially land in one tight group and instakill enemies, big ones in particular. And we all know that it was too awesome on shard bombs to exist.

I tried a max dmg, level 6, nether cannon on depth 28 elite solo i. A decon zone (or maybe D27).

The charge is quite fun there, does some great damage. The invincitinks nmake sense, because one hitting everything is the FoVs job.

But srsly, the gun aint half bad.

I'm agree in 100% Why ? why ? why ??????????????????
Blitz have most awesome charge and haven't got invincy-thing...
Tortofist's charge deal falling DMG + just 3 hits from shards... why ? WHY ? Charge knock back so is really small chance to block anemy.

OK, I know you don't want too OP wepons BUT make 5-7 hits no 3, It will still won't be too OP but will be more useful; just make shards hit few more times, please !

I think that there is a time and a place for invincitinks, and that they're a bit too prevalent on certain things.

Shard bombs: Should probably not have invincitinks, as their damage is kind of pathetic and the mechanic just goes to make the bombs even worse, penalizing good play.

Barrier pickups: I can see why this would be a thing, but at the same time if you're able to get consistently next to an enemy, then you deserve to do the damage. I would rather the barriers deal more status effect and less damage, but not have invincitinks.

Seraphynx's Beam of Light: I'm not certain of how they want us to use this skill, or what its supposed to do. I am able to use it effectively to drill through rocks and ice fragments during certain fights (like Maulos), but its worthless for dealing damage-- especially compared to Drakon's fireball and Maskeraith's needles. I think removing the invincitinks would make the skill usable for dealing damage, but perhaps there is some utility benefit that I'm missing out on, and damage isn't its primary concern; like pushing mobs back, which is also messed up by invincitinks.

Tortoguns: I think the invincitinks here are almost entirely warranted. I am able to consistently trap enemies every few charges, and I deal a ton of damage already when this occurs; removing invincitinks would basically insta-kill even large mobs, like the jelly king, vanaduke, tortodrones, giant lichen colonies, you name it. You could argue that they should just nerf the damage and remove the invincitinks altoghether, but then mobs walking into the spikes that weren't trapped wouldn't take much damage at all, and the weapon wouldn't function properly. Making invincitinks activate after a few more hits would be nice, however... mostly because pushing mobs into the spikes deals some damage, but launching more shots onto them is a better tactic altogether.

They probably imported the code for Lava Tiles and reversed it for it to affect Monsters instead of Players, but don't want it to instagib Monsters stuck in them, the way Lava Tiles instagib players when they're caught it them. iono... this ineligant design seems fishy fishy to me.