It should be obvious that validity alone cannot be the sole reason for attendance at a Eucharistic Adoration, as there are valid but illicit sacraments available in various places. While it is true that the Church has pronounced on these illicit sacraments, yet it is also true that the Church has pronounced on the validity of these illicit sacraments as She allows those in danger of death to be associated with them in a very specific situation.
Considering the audience on this site, I don't think many are concerned with whether or not the sacrament was licit. Unless you're trying to say that the NO is illicit in which case please feel free to explain.
The Novus Ordo is to be avoided because it is doubtful. This is the entire basis for the traditionalist resistance of the new sacraments.
I avoid the NO not because I doubt it's validity or licitness, but rather because it is inferior to the TLM and usually harmful to souls. This coupled with abuses of the rite is plenty of reason to stay away. It's primarily the SV viewpoint that believes the NO to be doubtfully valid and certainly is NOT the "entire basis for traditionalist resistance".
I ask you, though, why you think the NO to be doubtful. So far we have (1) invalid ordinations, which does not apply to
all NO Masses and (2) improper wording, which in the example cited does not apply to Latin Masses and will be rectified in all English Masses late next year.