Why would they come to America if they thought poorly of it? Immigrating to the US is no trivial matter and requires a large commitment of time and effort. Of course immigrants think highly of the US. Whether or not their perception of America is based in reality is another matter entirely.
Most already are, or moving towards it. But no, that’s not a good thing.
Though, as America is still the global superpower, the debt really isn’t as important as you suggest, but of course I wouldn’t speak out against slashing defense spending and hiking taxes on wealthy individuals and big business.