Some good arguments from both sides here and I thought I'd put my two cents forward.
First of all, I'm certain that the Devs of the game have and do take a lot of attention at DotA mostly because this is a game which has evolved for over 4 years now through a very open environment. Good ideas were kept and bad were discarded organically (that is, simply by people's preferences). The result is a game with a lot of interesting gameplay and diversity from which to get an wealth of ideas.
If as a community those DotA experts promote ideas which could be of much use in DG, then it's likely we'll see implementations.
Diversity
The number of skills on the two games has been compared based on the number of characters and I think this is a valid point. But what you need to remember is that 8 skills on a character in play tactis is increasing the possible combos exponentially. In DotA as you level up, you can have 6 possible combinations of skills per character (assuming sticking to 2 main choices until you max out) and since after one point you can't level up one skill anymore and must switch to the others, in the end game the diversity of a build drops off. That is why you need a lot of characters to give it diversity.
As you increase the number of skills however the pairs options are much more. For 5 skills you have 10 pairs. For 6 skills you have 15 pairs and for 8 skills you have 27 pairs. I don't know how many skills each DG will end up having but if they have 12, then the possible tactics increase amazingly.
I do think that DG should avoid merging the end skills at the end game (as it seems to do now when one reaches level 25). I think that by allowing end-level chatracters to become "experts" at their selected build or diversify would increase the porential customization and play of each character. Thus I'd like to see the main skills increasing to 6, 7 or even 8 levels with possibly 2 "super" effect on that path, say one on level 5 and one on level 8 which give you an incentive to go all the way. The later levels of the skill should have increases and effects designed to punch through tanked out characters full of 12k items. An alternative would be to reduce the level cap but I think it would be better to give more options than less.
Perceived Superiority of DotA Quality over DG
It's unnecessary to say that DotA has existed for over 4 years now and as a result it has had an huge amount of time to improve and round out. Being community driven does not harm either since it allows hundreds or thousands of minds to cooperate with ideas and coding. On the other hand it is completely unfair to complain that DG looks unfinished, unbalanced and unpolished now and/or extrapolate that it will keep being like that in the future. It seems that since people paid for taking part in the beta, they forget that it is still a beta. We're probably not seeing even half of what the future will bring and that is because the devs are doing the very progressive thing of asking for player input while they are still in the development phase.
I think GPG should take a lot of note in player ideas as certainly they would give them concepts they did not think about. There's no better time than now to setup a brainstorm site and see what your audience wants.
But even if on launch date the game is still lacking in depth compared to DotA, Stardock has already proven that they value future support and will provide future patches and content for free. Galactic Civilization is a testament to that.
On tournaments and brackets
Some have mentioned that having brackets in tournaments means that people will prefer losing a few matches so as to continue being in a low bracket. But as SupCom has shown, there is also the way to separate your brackets by points. Simply matching people will ones who have +/- the same amount of win/loss ratio will defeat this "tactical loss" strategy (nevermind that I do not think that tactic makes any sense as if you ended up losing naturally too much in the higher bracket, you would drop again without meaning to)
Community
The reason why DotA has such a success in features is because it is crowdsourced. There's no chief above and no developer team they have to beg. I think that DG MUST give enough modding tools and capability to create a vibrant community around it. Part of the success of warcraft 3 and half-life was in how moddable they were. Give the people the tools to create new demigods (even if they cost 10k, btw where did we get that figure?) and they will do so. Give them the ability to create new items, new abilities, new maps and the like and then you will see unbound creativity.
The power of modding is that it allows the players to make the game they want to play and experiment in directions the devs didn't think about. If there's anything that DG owes its whole existence, that is to the modding scene who first thought of AoS and DotA and proved that they can be popular and there's a market for them. I think that if DG cares for them, any lack in the actual game will be able to be ammended.
Negativity
One last thing. I think both sides of this argument need to stop seeing the other as the enemy. Jinx and the like are not here to bash the game, their posts are because they want it to be as enjoyable as DotA is to them (note that I'm not saying "identical"). It is wholly wrong to bash them for doing constructive criticism when you should be encouraging it. We have a unique opportunity to imrpve the game "while the iron is hot", let's not waste it with assuming that everything will be perfect and shouting each other down.
On the other hand, criticisms need to be tempered in the knowledge that the game is still in beta and we're not seeing the whole picture. There's no point in ranting about "8 skills" when we don't know how many the end result will have. If there is a concern then state it and ask the devs for some info. Let's make criticisms that are actually valid.
That is all