Taking a systemic view (nodes of a graph containing money with edges representing debt), lending at interest must over time concentrate the currency in the hands of a few (essentially one node in the end). I deducted: The rich will get richer, the poor will get poorer
Why must it be the rich that lend to the poor? Rich people borrow funds all the time for their ventures, which ultimately come from the public.
Also, even if the rich do lend to the poor, the net effect needn't be that money flows from the poor to the rich. Rich person lends to poor(er) person; poor person starts a business; business makes product; rich person buys product, moving funds from the rich to the poor, possibly more than the interest paid.
and concluded: lending at interest is evil.
Why would it be evil? For whatever reason, the borrower values X now more than X+e later. He willingly enters an agreement where he gets X now and gives X+e later. Both the borrower and the lender benefit from this. When borrowing for a business, presumably the borrower makes a net positive monetary gain from the loan.
It is only evil if the lender works to create harmful conditions for the borrower which cause him to need the loan, or deceive him into thinking he needs the loan. The same as any other business.
I deemed this view of mine validated by observing the rich actually becoming richer and the poor becoming ever poorer.
Logic fail, assuming you mean by "validated" anything more than very weak evidence.
Since fractional reserve lending is not possible with bitcoin
What do you mean by this? All the big lenders in this forum are fractional reserve, they take deposits, keep a small fraction in reserve, and lend out the rest to create a return on investment.
Fractional reserve banking, where people deposit funds for reasons other than receiving interest, and the bank does not keep it in full reserve, is obviously also possible with Bitcoin. It's just less likely to be common, because with Bitcoin there's not much need for a bank anyway.