I won't question God's motives. He tells Moses-- and this has to be a paraphrase because I haven't found it yet but will, it's in Exodus, I believe. That He will be merciful to whom He will be merciful and if He choses not to, well that's an option too.
You conviently skipped a very relevant part of Paul's first letter to Timothy:
4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
5 Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will,
6 To the praise of the glory of his grace, wherein he hath made us accepted in the beloved.
7 In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace;
8 Wherein he hath abounded toward us in all wisdom and prudence;
9 Having made known unto us the mystery of his will, according to his good pleasure which he hath purposed in himself:
10 That in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; even in him:
11 In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will:
You conviently skipped a very relevant part of Paul's first letter to Timothy:
Very relevant. The great thing that the Reformers put aside was Gospel, then NT, then OT inclusion. We Catholics use the mathematical operator "and". Therefore, we have Jesus willing all men to be saved; we have Jesus predestining people to receive His inheritance (eternal salvation); we have people that reject that inheritance. We must put all of these ideas together, and not engage in duelling verse. We do further believe that the NT must be read through the prism of the Gospels and the OT must be read through the prism of the NT. This also sets us apart from many of the Reformers who began to pick and choose certain selections of verse that they liked better (the epistles of Paul, and the book of Isaiah, for instance) to supersede Gospel teachings.
Astute and relevant, sir. However I would urge you to consider the traditional Catholic viewpoint of Biblical inclusion, with the words of Jesus more important and more relevant than, say, the words of the Chronicler in 2 Chronicles 25.