The God of the Old Testament is arguably the most unpleasant character in all fiction:
well -- firstly, we'd argue that the OT is not fiction.
Secondly, that veers on Marcionism, actually it IS Marcionism or Manichaenism(namely OT God - bad, Jesus = Good guy)
And thirdly, with the same fault as point 2, it's not quite correct. the OT God IS compassion:
Biblegateway search for compassion
The OT God does love: Deut 7:8 "Because the Lord loved you", Deut 7:9 "he is the faithful God, keeping his covenant of love to a thousand generations of those who love him and keep his commandments.",Deut 10:18 "(he) loves the foreigner residing among you",