I agree they should've that they should've added alien tech that would give them new capabilities, but I disagree with the whole "Patchwork" ship thing to the point it's some ugly mish-mash. The other Trek shows showed them as being better than that.
I mean hell, in Farscape they added new tech to Moya but it didn't change her appearance or anything.
A patchwork look gives a better impression of being forced to make do and improvise to survive. Voyager shouldn't have been operating like other trek shows, there should have been a more clear distinction between her situation and Enterprise D on an exploration cruise.
Can't comment on Farscape, never watched it.
But if they couldn't make new allies and figure out how to repair the ship in strange circumstances, they'd look like idiots compared to TOS and TNG. Yes, I can see some patchwork stuff done maybe on the inside but the whole ship becoming some ugly mish-mash is too far and would make them too incompetent.