The Knight World list has had the option for Titan allies for many years with no problems but since taking over Dave has made the bizarre decision to remove titans from the list, which I think to be highly inappropriate. I wanted to run a poll and get some discussion on it as Dave has ignored my objections so far.

The background (old and new) describes the Adeptus Mechanicus having far closer links with the Knight Worlds than they have with the Imperial Guard or the Space Marines. Titans have often fought alongside Knights and were closely associated together in the SM2/Titan Legions era in particular. Knight Worlds are closely linked with a nearby Forge World and are stated to provide most of their Forge World's food and raw materials. Hence if a Knight World is attacked the AM has a direct interest in seeing it safe and much more likely to send a Titan Legion contingent to fight amongst the planetary defence force than it is to send them to support the SM or IG in one of the Imperiums many wars (the background is clear in many places that the AM are independent and cautious with their titans and primarily look out for their own interests, often refusing requests for aid from the wider Imperium). Thematically and aesthetically Titans and Knights also fit well together, being walking robots with heraldry and banners.

Apparently rather than developing one Knight World list Dave has the idea of splitting the list, to have a Knight World PDF and a separate Knight and Titan crusade list at some future point, maybe, but there's really no need. Titans would be likely to fight alongside a Knight World PDF and leaving Titans out to be added back in to some future Knights + Titans list dissatisfies players wanting this now and unnecessarily splits a limited amount of playtesting between multiple lists, lengthening the time it takes to get an approved Knights list. A single Knight World list can well represent it either defending it's planet or out on crusade (just as there's a single SM list not separate lists for ground pounder and air marines say).

If Dave isn't so keen on titans he should simply not take any in his own lists not force this restriction on the list. A good potential compromise could be to include Titan allies, but not the option for a single Warhound. They can then still be used, but not so casually or commonly, as the titan formation is more likely to be the BTS. Titans but no singleton Warhounds is the way the Space Wolves list has it too.

Instead of a poll, couldn't you just have written this post in the V2 list thread?
Setting up a poll, whilst using obviously biased language in the description is not going to help come up with useful position.

I don't see titans as integral or necessary to the Knight list. While it is true that Knights fight alongside titan legions and many swear allegiance to the AdMech, I think it encourages armies that presents titan legions as supporting Knight armies when I would gather that the opposite is more likely to be true.

As it's own list, knights shouldn't have titans of any kind freely available as allies. However, at some point it wouldn't be out of place if knights appeared as either allies or limited selection units in other AdMech lists to allow for fluffy scenarios where Knight households are called upon by the AdMech to support a battle or campaign elsewhere.

I think it encourages armies that presents titan legions as supporting Knight armies when I would gather that the opposite is more likely to be true.

A dual quake reaver would vastly outperform 3-6 Crusader/Castellans both in damage output and survivability, for example. Warhounds offer fast moving flanking power with MW and vulcans... but a squad of Lancers can and should be pretty comparable (though perhaps less durable than a pair of warhounds).

I know the focus on the boards here is on designing whole-package lists that represent a single theme, but playing a larger game with smaller individual detachments often seems to me to be the easiest way to represent some of the...messier combinations. Two internally-balanced lists paired up for a doubles game is a lot easier to manage design for than trying to cram too many different toys into a single list and keep it reasonable.

On that thread you linked to the following were in favor of a titan-less PDF list:

Armiger84, E&C, Koshi, wargame_insomniac, DaR, DS, mordoten, Markco, Borka

And the following for a crusade force with titan-allies but no PDF elements:
Rastamann, PFE