Can not speak for the original poster, but I tend to agree in that it greatly limits the speed of creativity due to the integration process, creates a very subjective bureaucratic process for inclusion, and that frankly emoji are not a script (yes yes, you can make an argument that they are akin to ideograms, but this analogy breaks down rather quickly). Thus, I think a different technological solution could have been warranted. The story I keep hearing is that it was necessary to get the Japanese telephone companies on board with Unicode rather than their own emoji hacks combined with local Japanese encodings, which I can sympathise with as a necessary (but unfortunate) evil. A word of caution though that I find text with heavy use of emoji largely unreadable as my eyes fixates on the emoji rather than following the text; thus I am likely biased (but possibly still correct).
All things aside though, Han unification [1] remains the worst part of Unicode to me as it makes it impossible to know whether the glyph I am seeing is the one intended by whoever wrote the text (Chinese names in e-mails for example is an utter mess for someone like me that has to have their system set up to mostly handle English and Japanese). The whole Han unification mess more or less necessitates markup and sometimes even the insertions of raster image glyphs for historical and regional texts which is just bloody daft. Yes, Unicode language markers do exist and can resolve this in part. But, they are invisible to the end user, can disappear while copying and pasting, and you have to rely on the original author even putting them there in the first place! Whenever someone struggles to see the issue, I usually propose that we unify the common subsets of the Cyrillic, Greek, Latin, and Mathematical glyphs which usually finally drives home the point.