I actually kind of liked that. It didn't take just the races of the present cycle to defeat the Reapers, but the combined efforts of all those who came before (or at least those who contributed to the Crucible, that is). Those species who fell to the Reapers in the past were at least able to gain some measure of revenge.
The main problem I have with it is that it relies of the Reapers being completely naive at best, monumentally stupid at worst.
The Crucible plans have spanned countless cycles, the Reapers know this. From the pattern of progression they can see that each cycle gets incrementally closer, hence the previous cycle actually built the thing, they just ran out of time to deploy it. Despite having access to the plans in at least the previous cycle the Reapers make no attempt to sabotage them for the following cycle, they just stop at destroying the Prothean version of the Crucible, despite all evidence suggesting that the following cycle would, somehow, get the plans. They also develop no countermeasures. You could argue that this is supreme arrogance on the part of the Reapers in that they do not expect anyone to actually be in a position to use it, but the fact that the Protheans actually built it should have been warning enough that a subsequent cycle might take things one step further and not only build it, but deploy it.
Instead, they do nothing.
In certain ways Refuse is the best ending. You sacrifice the "win on the Catalyst's terms" in this cycle for a clean win in the next. The following cycle wins without having to fight the Reapers.