Gilmore gets a bad rap but lets remember he didn't inherit much besides Day, Rochell & Romeo O. He oversaw the development of Jillery as a Fr. DT that year. He was also the DLine coach of record that brought in the '16 class of Okwara, Jones, Kareem (who he stole from Bama becuz of his relationship with Kareem's dad) and Ade O who decommitted from Fleck when Gilmore targeted him. Without Gilmore, that's a HUGE difference even going into next year. Gilmore landed or started the recruitments of Hayes, Ade O, the Ademilola's, Hinish and Ovie O. His legacy lives on big time.
That above earns him eternal reps plus D Ewell was a huge win at the time. Now, he does get some deductions for missing on the Ewell eval and for being the guy who brought in McCollister I guess but he's still net positive, by a bunch.
Also of note, I remember Sheldon Day publicly calling BK out for letting Gilmore go. Called him one of the best DL coaches in the country. Safe to say, he liked Gilmore more than Elston.
Last thought... he kinda started behind the 8 ball because of the '15 class he inherited. Besides Jillery it was the infamous 2 filler DT's = Tiassum & MDT plus Elijah Taylor never developed. On top of that, add the huge (and terrible) DL class of 2014. Elston basically got his DL job back by stocking Gilmore's room with 2 bad classes and then inherited Gilmore's 2016 haul + Hinish, The Ademilola's and Ovie O.