NOTE: Please try not to become defensive. The topic isn't meant to attack God and/or somebody's belief in God; it's only to initiate an academic bull session.
• Gen 6:5 . . And the Lord saw that the evil of man was great in the earth, and every imagination of his heart was only evil all the time.
Man's descent into depravity didn't catch his creator by surprise. After all; not only can God see the future but He can also manipulate it; so He was well aware even before beginning that the people He was about to create were destined from day one for a global deluge.
Also, when God inspected His handiwork at Gen 1:31, He evaluated it not just good, but "very" good. So as far as He was concerned; everything went smoothly and according to plan-- nothing was broken, no parts were missing, and nothing failed to mate with its matching part.
• Gen 6:6 . . And the Lord regretted that He had made man upon the earth, and He became grieved in His heart.
When God created the people of man, it was no doubt with the awareness that the day would come when He would have to put a number of them down like dogs gone mad with rabies.
If it can be safely assumed that God saw man's depravity coming well in advance-- prior to creating even one of the many forces, energies, and particles that would go into the construction of the cosmos --then we have to wonder why it is that He felt remorse for going ahead as planned. Surely it wasn't because He made a terrible mistake. I seriously doubt that a master architect with the creator's intelligence would fail to foresee every possible ramification of their actions.
Well; it's at least comforting to know the destruction of life is not something God enjoys as if He were an outdoor guy who kills fish and wildlife for sport with no more sensitivity than a kid blasting aliens in a video game. Man's creator knew the day was coming when He would have to do what He was about to do next, and clearly wasn't looking forward to it, but nevertheless; leaves us with unavoidable questions about His sanity because from a rational perspective, God's procedures make no sense at all.
Anyway, aside from all that; it appears to me that God had high expectations for the people of man, and was very disappointed that numbers of them went bad; sort of like how parents feel when a kid, whom they've given every privilege, every opportunity, and every advantage imaginable, lets it all go overboard and somehow ends up incorrigible and a total failure instead.
• Gen 6:7 . . And the Lord said: I will blot out man, whom I created, from upon the face of the earth, from man to cattle to creeping thing, to the fowl of the heavens, for I regret that I made them.