Do you have any examples of games in which players have actually done this? It's quite a poor strategy, and I can't think of any players who would do such a thing.
it doesnt happen often and it's a bad tactic in 99% of the cases. At best you are breaking even on the amount of troops you get, but more often than not you'll get less troops than you would have gotten if you didn't miss a turn. And you'll get them at the end of your turn as well, instead of at the start.
I already see that happening in round limit games. One player is leader, and decide to miss 2 turns, that way the other players have more troops than him at the final turn and don't think he can win the game. Then he comes back for the final turn, got the deferred troops from last 2 turns, and win the game with the round limit.
Nevertheless this is a rare case, and I agree that in most of the case people miss turn unintentionnaly,and don't gain any advantage from it, quite the contrary, and so deferred troops are only giving them a small chance to still win the game. We shouldn't suppress them