Can we address this "filler is bad" mentality? I'm not sure that I agree. What are we defining as filler and what are we defining as bad?
I think we're about to get into a definitional war similar to the "tempo" debate that will derail this thread and offer little value, but since I stirred the pot, let me be the first to really address it.
Filler is there. Filler is here. Filler is now, and filler is you and me. Anything is filler depending on your angle.
Doom Blade might be called "filler removal" because it doesn't serve any purpose but to box-check cube removal counts.
Savannah Lions might be called "white aggro filler" for a similar reason. Same with
Disenchant or perhaps
Boros Signet. Somebody will disagree with all of those assessments and won't be wrong or right for it. So, recognize from the start: filler has a lot of meanings and isn't a useful term until contextualized.
I'm not blindly opposed to all filler. I think a degree of filler is necessary. I run some cards that, while likeable, are arguably just filler.
My issue with filler is when it feels "bad". I don't like "bad filler". Bad filler to me is a large colourless creature section to allow decks to soak up bodies. Bad filler to me is lots of colourless removal so any colour can go control. It is not necessarily wrong, or bad, or unplayable, but for me, philosophically, it is undesirable. I draft primarily with one other very skilled drafter and one of a handful of (a growing number of) friends, so I can afford the luxury of being more demanding, because so are my drafters. We are not Spikes; we are impatient Johnnies and Timmies who despise casting things that are simply vanilla creatures. It just doesn't interest us. So bad filler to me = vanilla creatures and too much colourless stuff just to fill gaps.
More specifically, my issue with filler is when it's stuff almost anyone can get use out of that is virtually always the least desirable option if you had the choice. Stuff in my cube previously that I considered filler was
Steel Hellkite; an efficient, colourless creature anyone could draft as a closer without having to really try, because it was colourless and somewhat inferior to most options in-colour. I am opposed to this sort of "dregs of the draft" filler that will only be picked up at the bottom of a pack by most players outside of a dire need for its effect, because it isn't exciting. My playgroup has fun building decks that reward clever crafting, while also playing in a format that is powerful enough to allow even the most tuned decks real competition from those that didn't totally get there. If people oppose this philosophy, that's fine, but I'm well aware that filler is something we arguably all use; it's a matter of definitions, though, and I think by the end of it we'll all be splitting hairs unproductively.
tl;dr - I don't like Endless One because it bores me and my playgroup doesn't like boring-but-playables. YPMV and if it does, go nuts!