Upvote:4
The UK decision-making process for visitors does not acknowledge purchased flight tickets as evidence and they do not refuse applicants on that basis. This is a difference from the Schengen decision-making process where confirmed arrangements are needed. There has been an advisory on the the UK site recommending that the applicant NOT purchase tickets in advance of an approval.
They already know for example that tickets can be refunded or even abandoned. Confirmations can be forged. They also know that a person who wants to abuse a visa (or overstay, or deal drugs, etc) can quite easily purchase tickets. In fact, anybody with a credit card can purchase air tickets, but what does it prove? Moreover, they already know about all the tricks one finds on the internet about printing off confirmations and cancelling them or other ways to game the airline reservation systems. So the bottom line is that they will ignore purchased air tickets as evidence. If anything, it's harmful because it shows you did not read the guidance.
Reading the text from your refusal notice helps to clarify the ECO's grounds for your wife's refusal, namely that she did not appear to be a genuine visitor. Instead, she appeared to be a person joining a spouse who was in the UK on a Tier 2 Inter-company transfer (T2 ICT). This is a different category of visa with different terms and conditions. Based upon all that's given, she simply applied in the wrong category.
For your last question, your wife can submit a fresh application any time, and there is no 'cooling off' period between successive applications. However, she should not apply as a visitor because the ECO made it clear that she cannot qualify in that category. Instead, she should apply as a T2 dependent.
You can ask more questions about that kind of application at https://expatriates.stackexchange.com/questions
Adding...
This answer applies to people who must apply for entry clearance at a foreign issuing post outside the UK. People who can come to the UK "on their passport" will always need to show tickets because they are already here. Different rules apply in those cases.
The new guidance published yesterday states explicitly that they DO NOT want to see hotel bookings and flight bookings. Their intent is to eliminate a long-standing public confusion about it. The original answer is not changed, but there's now clarity in the guidance.