In my view the Paragon vs Renegade arguments stem from two simple factors; validation and tone. Paragon decisions are regularly validated by the game, even if there is no actual impact. I'll keep it to the big ones for ME1 the Rachni and the Council. The messenger on Illium validates the Rachni choice; they're thriving, they're willing to help, and they seem to have peaceful intentions. The Council decision is also validated with the Council agreeing to meet with you and expressing that they do, to an extent, have faith in your judgement.
This is great, it is fantastic that the player's choices are validated, even if actual consequences seem lacking. However it also creates a problem because these invalidate the Renegade choices. While you can play these as "KILL D'EM 4 TEH LULZ!!" the choices seem to focus around risk. Given the damage the Rachni Wars caused letting the Rachni go free is too big of a risk and you terminate them. With the Council the risk of not having enough firepower to take down Sovereign before he overrides Vigil's block and opens the relay is too great so you abandon them to their fate. The Paragon choices turning out well entirely invalidates these choices because it renders the sacrifice unnecessary.
This brings us to the issue of tone; again while the choices we made don't have any real impact on the game the tone they set does have an effect on the player. The tone of the Paraverse is almost entirely positive; The Council races love humanity, the possible return of the Rachni doesn't seem to have upset anyone, and the Alliance doesn't seem any worse for the loss of 8 cruisers. This is in contrast to the Reneverse which is very much negative; The Council races hate humanity, there seems to be a Cold War brewing between the Alliance and the Turians, and for all we're told there's a human run/controlled Council there's nothing that actually suggests the Alliance is any more powerful than they were.
In fact if you look at how all the ME1 Renegade choices are presented in ME2 they all carry this tone; the player is lead to feel that their actions had no upside to them and the sacrifices they made were completely pointless.
Fixes to the tone actually wouldn't have been that hard, since most of it comes from primarily passive interaction with the game world. For the Paragons just throw in a few downers; imply that the Alliance is still recovering from the loss of the cruisers used to save the Council, suggest there's unrest amongst the populace over Alliance kowtowing to the aliens, give us a news report that people are militarizing and hunting in response to the possible return of the Rachni. Keep the positive outcomes of the choices (Good relations with the aliens and Rachni allies), but give the player the impression that they, or the Alliance, have paid for these.
And do the same thing for the Renegade, keep the consequences (dead rachni, anti-human sentiment) but give the player some indication that they got something out of it. A stronger Alliance military, some examples of humanity brow beating the other races, just little things that effect nothing (now or later) but let the player say, "Well at least I got something."
And fixing the tone almost completely solves the validation issue, because while the Paragon players may be considered to have gotten the better deal there was a cost to it which the player can assign as the value of the sacrifice they made. Both players feel as though they've made gains and taken losses as opposed to one player feeling as though they've gained nothing while another player has gained much at no cost. You can't make it perfect without making all choices meaningless, whenever you have two options one of them has to be the better one, but you can make it better.