In this particular sentence, I believe the verb can only be in the plural. According to my favorite Grevisse (Le français correct, 1984):
(985) Subjects linked by AINSI QUE, COMME, AVEC, etc.
a) If the conjunction is copulative ( = aggregates subject elements), the verb agrees with the whole: Le français ainsi que l'italien DÉRIVENT du latin (Littré). - Aussi bien l'oncle Mathieu que tante Philomène n'ÉTAIENT pour moi que sons (H. Bosco). - La voix non plus que la silhouette ne lui ÉTAIENT connues (A. de Châteaubriant). - Le murmure des sources avec le hennissement des licornes se MÊLENT à leurs voix (Flaubert). - L'une comme l'autre GARDENT peu de loisir disponible pour l'aventure (M. Prévost). - Tant le sol boueux que l'eau m'ÉTAIENT présents (H. Bosco).
b) If the conjunction clearly puts the elements in comparision, the agreement is with the first element:
Le français, ainsi que l'italien, DÉRIVE du latin (Littré). - Son visage, aussi bien que son cœur, AVAIT rajeuni de dix ans (Musset). - Le manque d'air ici, autant que l'ennui, FAIT bâiller (A. Gide). - L'un comme l'autre EST pris au jeu (Id.). - La religion, comme la politique, A ses Brutus (A. Hermant). - Renée, pas plus que Gilbert, n'ÉTAIT retournée chez les Guillaume (M. Arland).Same (with AVEC), if one element is clearly accessory to the other:
Le travail avec ses servitudes lui INSPIRA de bonne heure un grand dégoût (M. Garçon).
In the present case, the mix of similitudes & divergences neither approaches nor opposes the desire to master the language; they are just two juxtaposed, separate incentives. The conjunction is copulative in meaning, not comparative, whence:
... m'ont toujours motivé.
(Edited after jlliagre's comments)
Disclaimer. My approach is descriptive not prescriptive, maybe I should add this to my SE profile. I am not a party in any effort at normalizing French, only explaining how I write it.
In particular, I write w/o regard to the ongoing normalization process. I guess it systematically moves towards relaxing the rules I follow, not toward invalidating them; I have not checked though. End of disclaimer.
Back to the question at hand: on the prescriptive side and as far as I know (which need not include the latest news, see above), school teachers are now instructed to accept both singular and plural in every instance, as reflecting the 2 equally valid intents of the writer.
Finally, I will add a word about commas. Grevisse's examples clearly show they are optional and somehow related to the chosen agreement: his editors, if noone else, prefer them with the singular. However, he has not a word about them in the entire section I quoted, so I believe the subject is quite distinct.
My own opinion is, punctuation comes after deciding the contents of the text and the comma basically marks where speakers breathe;pause; if they help silent readers (which they certainly do, so typesetters and editors will inevitably have their say about this), it is secondary.