On the contrary, I feel that it is a good feature, not a problem of the game / recipe design. It is one thing which needs different solutions than most other building / ressource problems in factorio. As variety adds to the attraction of a game, this is a good feature. Arguably, it is a more difficult challenge than most other items, but that's not bad design either.
So IMHO it boils down to "does the game need to follow one concept for every product or allow for additional concepts.
There currently are three methods of production (excluding manual, and ignore exact amount of input items) afaik:
method 1 (all stuff except space science and oil): input Y1 ... Y6. Output A, stop when A is in excess
method 2 (space science): Input Y1 ... Y6. Output A, but just waste A when it is in excess
method 3 (oil): Input Y1 ... Y6, Output A, B and C, and stop when any output is in excess.
Arguably there is missing the intermediate step between (1) and (3) which might act as a teaching aid (though I don't think it's needed):
method 4: Input Y1 ... Y6, Output A, B, and C and just waste when any of A, B, C is in excess
and maybe
method 5: Input Y1 ... Y6, Ouptut A, B, and C, and stop when all outputs are in excess
Consistency with only one principle of production in the eintire game would, yes, make it easier, but also reduce the game's appeal and variety to people who like to puzzle and solve problems. The latter is probably a HUGE part of factorio's player base. A game need to be able to play-through on first take without 2nd thought once you understood one principle. It's ok and appealing (and far from appalling) to stumble over oil, take a step back and wonder what you need to do to solve this issue.