Goto did say he would pick revan over malak, That malaks military tactics and strategies were painfully obvious to everybody,
Not exactly stupidity but in my point of view he indirectly says that.
Only a complete fool wouldnt know how to make strategies which are decent and not so give away
Even jan dadonna stated that her fleet can do a formation to defeat malaks fleet during the SF battle but were unable to due to battle meditation, That proves how useless malak is as a leader and he needs some body to do his dirty work
Don't forget that Darth Sion appreciated Malak very much.
The search on Taris was taking too long and it was due to exploits of Revan and Canderous that Bastilla and other companions made out alive.
Canderous made it possible to get the Ebon Hawk in time. Revan won Bastilla's freedom. So all these things count.
Malak did not wanted Bastilla to live after his success against Republic Fores above Taris, so he ordered to destroy the entire world. Though it was a very cruel act.