The problem is that the trilogy still has plenty of unanswered questions left regarding the state of the galaxy after the war. There still not enough resolution for the trilogy.
It's not Bioware refuses to deal with issue's they've made in the trilogy, they've learned nothing from them.
It's true that they don't want to deal with the endings. That doesn't mean they didn't learn anything. That last point remains to be seen.
Ignoring just means that they don't want to deal with the issue's they've made, Bioware is pretending the issue's they've made never happened.
If Bioware is ditching the MW for good then the choices made in ME1-3 are pointless since there is no point in saving it, the reapers might as well win.
This is going a bit too far. They don't pretend it never happened, nor are your choices in the trilogy pointless, just because the next game will probably have a scenario where these choices do not have an impact.
In fact, the opposite is the case. If they were to make another game in the MW (and I exclude the possibility that they make 3 games, one for each ending of ME3), than they would have to pretend that the player never had a choice and they would have to make the choices pointless in order to tell a new story. This way, they don't have to contradict anything and we are still free to headcanon what happened after we finished ME3 in the milky way.
Besides, who is to say that - just because Andromeda takes a side step to another galaxy - no future ME product will take us back.
@Nethershadow: I am afraid we have nothing else to go on but these epilogues, so that has to be the material we need to work with, whether you find it plausible or not (I have my problems with its plausibility as well but hey, it's done).
On the other accounts: BW has never made any ending choice canon. All choices are accounted for in the later ME games (apart from a few unfortunate bugs like Conrad Verner in ME2). The trilogy has no canon.
We are also not playing another N7 guy, whether the new protagonist will be alliance or not (or whether the alliance even exists in Andromeds) is unknown.
While it is not entirely certain that nothing out of our galaxy is affected by the crucible, the wave spreads through the relay network, which -according to it's own builders - only exists in the Milky Way. Besides, it would be a really odd choice by the writers to send us all the way to Andromeda in order to escape the ending dilemma, only to use another contrivance to send that dilemma right there with us. Ultimately, it's the writers choice.