Arthur is wrong, again.
NetCapital hasn't purchased all of the debt, so you can't assign all of the interest owed as going to them. The debt conversion reduces the outstanding debt owed NetCapital.
If all $14M in debt was converted at $0.25/share, that increases the shares by 56M, but eliminates all of the long-term debt. Go back one month and ask yourself if you thought such a deal was even in the realm of possibility, when the PPS was under $0.01. At that time, it would be like eliminating the debt for $0.04 on the dollar.
Now, why would the original lender sell the debt at a 75% discount and why would NetCapital purchase the debt and convert it to shares? Answer: because NetCapital is bringing another deal together; one that wasn't available to the original lender. Those that can make the deals, stand to reap the rewards.