They're not horrible alternatives, it's just that CCC was so insanely good that anything other than CCC makes it look way worse than it actually is.
Also, popularity doesn't mean it's not good. There are plenty of quests that aren't popular but are actually very good quests to run for specific drops.
I've also seen a lot of sentiment around CCC being nerfed specifically for cookie farming for Halloween. I cant stress enough how bad of a take that is. There is zero chance that they would nerf a quest centered around one specific 2 week mini-event, that's preposterous. CCC was obviously insanely good for what farms were capable in it, so good in fact that it gets spammed constantly for the ID's its good in for their respective weeks, which completely blows everything else out of the water.
Dispelling the rumor now that CCC was nerfed because of cookie farming. That is an extremely disingenuous take people are seriously trying to push in regards to this quest. Its silly.
		
		
	 
They are in fact horrible alternatives. OP tried to help doomers by providing what they believe are solid alternatives. Nobody came into the topic asking about how balanced the quests are, or how "good" the quests are. Horrible alternatives in this context means they do not satisfy someone looking for a CCC substitute.
I don't particularly care about this change if I'm being honest (since I only use it for ranger levels pre-ultimate anyway) - it just seems disingenuous that people say there 
are alternatives. 
Well that and it took like 8 years lol
Due to a large number of enemies being weak to hell or otherwise easily combo killable in one small room, no other quest comes close to the efficiency when it comes to farming kills (edit: ...with drops.) There are 108 enemies in the Temple room alone, and 142 in Spaceship. While there are even more after this, most people get filtered or just don't find it as quick/efficient.
I did point out Tyrell's Ego as an exception and would probably amend that to say you can just run Forest resets. At 201 enemies this is comparable if you split as the runs pile up. CCC should still win due to map travelling but the doomers have a place. So...one is a decent, maybe good alternative. :^)
And I 100% believe this quest was nerfed due to cookie (and possibly badge/christmas) abuse. I think anyone implying otherwise is just shit posting or playing too much theory. CCC doesn't have any insanely good hunts - and it isn't included in RBR. Just look at the stand outs for time/effort spent:
Lilies/Rappies - most noteworthy due to being only short quest with both. Lost Shock Rifle works as a replacement hunt but it is slower; there are better options for hunting the enemies separately (MA2/Shock Rifle resets)
Bears - MA2 reset is better.
Belra - this is actually a pretty good case where nothing can really come close. but...nobody really looks for hit milla or yasha from belra.
Whitill kinda has a DoB hunt in Temple portion but PW1 exists. Still, DoB hunt + Rambling May was strong...
Delsaber - Strong, but falls behind LBA during RBR. Falls behind in a vacuum when considering GDV. Generally people are looking for Baranz combo hunts outside of Greenil however, which is also working against CCC.
PArms - actually not sure. 6-3 should be better? But GDV again when considering all drops.
Sorc - not exactly sought after for the most part but falls behind PSurge 2
CCA, Seabed, and Tower are generally too difficult for the average player to reach and clear but also take a considerable amount of time to reach in comparison to Temple and maybe Spaceship. Considerable as in every enemy has a better, quicker hunt option available. Outside of Epsilon the enemy counts after Spaceship are actually fairly low. Probably to compensate for TTK on the variety of minibosses and Epsilon?
(with all that being said, Pinkal and Whitill had very strong combined drops for CCC compared to other IDs, though I wouldn't call them 
insane)
It is fine to say they were insane once you factored in event drops, though. 
There were a few people who thought CCC should have drops disabled but the vast majority of people did not seem to care
 until it got removed lol. Besides the event abuse, I think the only other reason CCC had drops disabled was that Ultima already had the drops for it disabled...so it is easy to argue it should have never had drops to begin with.
Anyway, 
doopliss is probably shit posting as usual but Classic Temple is essentially worthless. You have Yellow 3084 and Whitill DoBs (which are invalid because PW1), nothing else. Ephinea Temple is hard to call neglected considering it now has the additional Rambling May, Vivienne, FS, Irista, Thirteen, Surpressed Heart, Morolian, etc...