I agree with every single one of the things the original poster said. I also come from DotA to demigod. I would like to point out I am in no way biased towards Dota. I love Demigod as well now. I almost exclusively play Demigod. I am very happy with it. I'm just greedy and always want more. But... I have friends who still play Dota and have not been converted. I also have friends who play dota who I got to buy Demigod, who are not happy with it - and returned to playing Dota. I hope the Demigod community (and financial investors) realize how much potential community they can pull away from Dota.
The magic of dota comes from years of refinement by an activity community. Please listen to players like Ghostnote because he knows what he is talking about!
However, I understand than many people come to Demigod and probably have never played dota. Dota is a fantastic game. It's graphics system cannot compare to Demigod, but for replay value and longevitiy its the game itself thats important - not the graphics. Demigod succeeds on many levels, but for many Dota players it just isn't enough. Dota players expect Demigod to be everything Dota is and MORE. That's what we feel a "Dota-inspiried game" should be.
I would like to respond to some of Ron Lugge's comments and reiterate that I am not biased towards any particular game. Each of my responses below portrays my opinion in terms of what would be more fun.
"Sounds more like micro-hell to me, and completely disinteresting. Not to mention unecesarrily gamey."
- Last hitting and denying is a huge part of DotA, and its fun. It gives you something to do at all points in the game. It adds another dimension of skill and interest to the game. However, I don't think this feature in Demigod is absolutely necessary if we have other things to replace it. The overall depth and gameplay of Demigod I feel doesn't really need last-hitting and denying IMO. Since playing more Demigod lately, I haven't missed last hitting or denying whatsoever since I feel there is more of a strategic element in Demigod and that makes up for it.
"You need more detail -- what's 'creep denial'?"
- Creep denial goes hand in hand with last-hitting creeps. In DotA, you receive a nice little gold bonus if you manage to get the last hit on a creep. Similarily, when an opponent creep is below a certain threshold you can attack it. By getting the last hit on your opponents creeps (or towers) you essentially prevent them from getting any gold bonus. In dota this is listed is a "deny" in the internal score system and doesn't really give you anything other than bragging rights. But its fun.
"That said, several maps provide more than 2 lanes -- Leviathan has 2 'starter' lanes, plus two neutral portals for two more lanes. Same for Ziggurat."
- Good point. I agree with you on this.. I haven't really noticed a lack of lanes in the game. But I do agree with the poster that I would like the creeps in Demigod to use more of the available space. To add my own thoughts: I honestly thing the maps in Demigod just need to be worked on a bit more. I find it strange theres 9 maps in the game but only 8 demigods. For map to hero ratio thats a ratio of 9:8. In Dota your ratio is 1:92. I really hope that gap in the ratio is bridged at some point in the future 
"Other than that, there's a reason I tend to prefer to host with 'strong towers' and 'strong creeps' when I do a custom game; the creeps do need the extra "oomph", especially early game, and the failure of towers to scale drives me insane. The need to (massively) improve the citadel upgrades, IMO."
- I agree as well. The "default" settings could be easily updated to reflect this as 99% of people play on the default settings.
"Such as...? I've seen a use for most, if not all, of the items in the game, even if it's not a use I'm going to use."
I find this comment a bit curious, but maybe I'm misunderstanding. In dota every single item has a use - and probably has been used at some point or another by good players. I feel that the items in Dota have been crafted and reworked with the same care the heroes have over the years. I agree with the original poster that this is severely lacking in Demigod. This is compounded by the lack of recipes in Demigod. Imho recipes are fun - selling is not. Recipes give you the feeling of building to something greater than the sum of parts.
"Play some more; the DG's are extremely diverse. It's only in the extreme late game, if things have been dragging on far past the point that they should have ended (i. e. very nearly equal teams) that this becomes even close to true."
Perhaps you should take your own advice. As I play more, more and more games are getting to the extreme late game phase. Much of the time if Demigod has a novice player the game is practically over in 5 minutes due to this reason. (Opponent gets fed a huge item early game and its gg) In Demigod it really does seem like the skills are secondary. I can't really say it better than the original poster said but I would liek to add that the control bugs and freezing skills in Demigod only compound this problem. The attacks (boosted by huge items) are really the most reliable forms of DPS in the game right now.
"Player, not developer, problem. Take the rook; everyone insists that you have to tower farm (well, used to). But a properly played smash build can do a lot of damage."
I see both your points of view on this one. I feel the OP is talking about extreme late game here.
Thanks to both of you guys for your insightful posts. My intention is only to help this game grow and get better and learn whatever it can from other games.