The idea is good but needs a little re-adjustment, and that is, not all altcoins will be left out. It is true there are many altcoins today with more upcoming up as well, in the same way there are good altcoins which are good to hold, if worst comes to worst then top altcoins are worthwhile. In the same way, holding Bitcoin is always the best but in my own opinion I think it also pays to hold 1 or 2 altcoins could be major altcoins to be on the safer side or other altcoins with clear direction on what they want to achieve. If I were you, I would hold a good portion of Bitcoin with a lesser portion allocated to other altcoins..