I wasn't harsh, I was honest and direct. I also wasn't unreasonable because it is, after all, my opinion. Opinions tend to be unreasonable, but mine isn't. I didn't feel any harmonic foundation in this section, only a bunch of 4ths and thirds. By foundation, I meant a note that one could cling to in case of emergency. You certainly had chords and momentary foundations, but they weren't consistent or solid. Perhaps that IS the foundation, a lack of one.
You assume I'm thinking of Mahler (of whom I've never seen him "develop everything"). I wasn't. Even accompaniments should be developed to an extent or they become stagnant and boring, here it did. As a footnote, you might want to consider why the section does sound "very, very empty" without the viola line. I don't think the problem is the viola line, but the setting you put it in. The stuff around it (esp. the cello) is also stagnant (rhythmically). Two stagnant lines in one section cause problems.
I'll specify because you took this way overboard. Bars 54-57 were what I was thinking of actually. I didn't even notice the 4/1. :) I think to make life easier for the player, it should be written as 3 2/8 bars (or one 3/4 bar), then one 4/8 (or 2/4) bar. Having the crossing of the phrase into 2+3+2 land is unnecessary when nothing else is happening.
As for the 4/1, now that I saw it, it really isn't useful. Just write it as 4/4 as before. The 4/1 does give any meaningful information to the players. Simplicity is the best policy.
You assume again. I didn't care if it was pomp and circumstance, only that it provided closure. In this case there is none, simple as that.
Offended? Really? I kinda went out of my way to not be inflammatory. I respect what you're doing, your aesthetics, whatever, but when you ask for comments (i.e. opinions about the work), then I shall give them. If you didn't want comments that weren't glorious praises (exaggeration), then don't ask. As for backing, or justification (which is what I'm assuming you're asking for), it exists, just not on paper. I didn't want to write a whole essay for this little work and just gave you bullet points. Indeed, I didn't want you to just be tl;dr. Regardless, my opinion, while it has backing (hence reasonableness), I don't have to share it (or justify it) since it is, after all, an opinion. But I'm, if anything, being civil here.