I would put this in much stronger terms. The theory unambiguously indicates that changing from block reward to txn fees will fail under the current design unless mining becomes monopolized. A solution to this problem will need to be adopted eventually. There is a reasonable debate about what the right fix is and whether it is worth worrying about right now or not. The side that says txn fees will work as they stand is not supported by a theoretical argument.
Personally, I believe an idea similar to yours will be seriously considered as the block reward is pushed extremely low.
The success of changing from bitcoin rewards to transaction fees is still theoretical. I'm not saying it will not work, but it is theoretical and has been the topic of much discussion.