To accompany my in-laws and to visit Canada as well. My in-laws have also booked on the same onward flight. But we have different return tickets. I plan to stay for 19 days. My in-laws will stay for 3 months.
IMO, this is one of the main reasons why you have been refused:
1. As adults, your in-laws can travel on their own without you.
2. Your in-laws tickets indicate a stay of three months = You are likely to overstay = It explains the 'Family ties' refusal reason.
Also, not sure if your in-laws mentioned a visit of a few weeks in their applications, and now their tickets (which you included in your application) prove the contrary to their initial claims.
IMO again, if you want to have chances of a TRV approval:
1. Cancel your current tickets. Defer your plans to visit Canada by a few months after your in-laws' entry date.
2. Do not reapply until a few months later. And, when you apply don't give the purpose of visit as wanting to accompany your in-laws for the return flights home.
3. Prepare a detailed day-by-day itinerary of what you intend to do when you visit.... specific activities for each day, not broad/generic sightseeing plans.
4. Include a Travel History explanation for the last 10 years (tabular format): Visa details + entry/exit dates + purpose of each visit + color scan the UK, Ireland and Schengen visas.
5. Evidence of family ties: Wife and you live at the same address + marriage certificate + joint bank account/joint financial investments + an explanation she cannot travel due to work commitments
6. Focus on your employment + include must-return-by-a-specific-date work commitments with evidence
7. Include any other personal commitments to return home by a specific date with evidence
8. Include evidence of property ownership documents or a lease agreement in your name + other related evidence (NOT just a CA report)
9. Evidence of other family members who are dependent on you (financially or for your well-being). For example, your parents
10. Your mutual funds/ PPF can be shown as part of your overall financial situation. You cannot state these amounts in 'Funds available for my visit'