I would lift the ban if it is only for low quality posts and he has no other accounts with a history of bans.
Sure... so, did you just registered this account to post this? Or are you OP and think we are dumb enough to think you are a different user randomly suggesting a unban for yourself? 
regular people wouldn't worry about ban when they joined the forum in the first place
unless of course he has other intentions
than getting information and discussing bitcoin related stuff Is it normal to permanently ban someone for low quality posts on the first ban?
I think it's possible if that's all you do. I've seen multiple users these past few weeks that got permanent banned and the only possible (or at least evident) reason was that they were spamming (mainly in bounty threads) and/or writing in a thread to earn a bonus (which is against the rules and will get you perma banned).I obviously dont know if the OP is telling the truth but if he is he should be able to improve his quality, like is the case for others in his situation previously.
he made those posts just to increase his post counts and activities
others that wasn't banned most likely made crappy post content but not regarded as spam
if a newbie continuously makes useless posts, mods would label him as a spammer and ban him