If Munthirivallikal is watchable despite Mohanlal or because of Mohanlal, depending on which camp you are in, a lot of that credit goes to its script writer M.Sindhuraj and director Jibu Jacob and in part to Anoop Menon. Never been a big Anoop Menon fan, but I loved the way he played the character of a ladies' man in the age of social media and cell phones - Venukuttan.
For me the problem with Mohanlal movies - the ones after the 90s, is that the entire cast, script writers and directors genuflect before the presence of Mohanlal that they forget why they are there in the first place. It's not Mohanlal's fault that peoples jaws hit the ground in his god like presence. This movie is not free of such fawning over but there is an element of comedy and touches of reality which keep us entertained and hooked.
Mid-life crisis, life's regular crises and cries form the story line of this movie. It addresses the mid-way monotony and boredom of long term relationships.*SPOILER ALERT* In the movie, Mohanlal being the super human he is, succeeds in rekindling life into his vapid marriage with a little help from a red sari. While he is at it he also pulls of a rescue effort, extricating our next generation from teenage love, deemed sub-par compared to the love one might experience with one's life partner chosen through an arranged marriage.
...and thus the movie - Munthirivalllikal Thalirkkumbole (When Grapevines Bloom) ends with Mohnalal quoting Song of Solomon 7:12, a tribute to Padmarajan's masterpiece, Namukku Paarkkaan Munthirithoppukal (Vineyards for us to dwell in) which might have inspired its title and the choice of its main actor.