Here's a small list of problems with transferring a Pokemon from Gen I to Gen VI:
1. It'll need to get a gender.
2. Need to get an Ability.
3. Need to get a Nature.
4. Figure out how it'll Special stat will split. (since in Gen I the Special Attack and Special Defense stat both came off one stat called "Special". Now in Gen II they did it by basing both SpA and SpD off the Special IVs and that Pokemon's BST. Though IVs have changed since then as I'll explain below so doing that ain't possible)
5. IVs would just to a nightmare to figure out how'll those translate. (In Gen I & II the IVs were 4 bytes long for each of the five stats ranging each stat's value from 0 to 15. Gen III completely redid the system which is used now, each of the six stats are five bytes long now giving a value range of 0 to 31).
6. EVs have a similar problem (basically in Gen I & II there was really no "limit" to how high EVs can go, the game stopping at 65355 for each of the five stats. Gen III made the change of 510 EVs total and an individual stat's max of 255 (252 in Gen VI but that's more for efficiency sake as nothing changes). I suppose they could reset it back to 0 though).
And I'm sure there's other stuff I'm missing. Simply put, the data structure of what made a Pokemon has radically changed too much. If they want to "transfer" a Pokemon from the Gen I to Gen VI the easiest way would be to do a Pokemon Dream World thing, "upload" the information of the Gen I Pokemon to the Pokemon Bank and then have the bank recreate a Pokemon from scratch just using the nickname and Moves of the Gen I Pokemon. Whether it'll be any good or not who knows (or if they may want to do something special with it like giving it its Hidden Ability), but if you just want it for memory sake that's an option.