In this example, your superior mat wrestler was unable to score in his superior position. If he gets a single turn during the second period, the score is 12-8, and he is back to an escape and TD to tie the match scenario. This new scoring system would encourage activity and require the superior mat wrestler to do more than ride out to keep the match close. One turn though and they are right back in the match.
This is why I actually am in favor of only changing the riding time rule as a first step and leaving 2pt tds as is. If this were the case, the score would still be 8-5 with one min left, but the losing wrestler would either need two takedowns to tie the match or a td and a turn to win. That to me seems fairer than simply getting one td and a ride out as your only offensive points.