Good thread,. Some very interesting comments. Personally I wouldn't have bought the bitcoin.com domain. Did they have the money? Anyway, it could easily have led to confusion - who is doing what here? - hence loss of confidence in both the currency and the agency. Coinbase have done very well and are now highly regarded within the world of crypto, so a good decision in the end.
@Bob Hawkes, yes, people planning a business do pass names around. For instance, I'm involved in a triumverate planning to set up a new enterprise (nothing to do with domaining, tech or crypto). We have been discussing names in the context of domain name, trademarks and already registered names at Companies House* for months and have only very recently settled on a name. This is not the first time for me and I am sure it is a common occurrence during the initial planning stage.
How the domain is priced (BIN, make offer, auction, other) is far less important than its availability and coinciding with availability of the TM and the company name. Social media handles also count more than how the domain is priced but less than the first three considerations.
As for defensive or complimentary purchases, this depends upon a host of other factors including sector, available budget, how many other TLDs are taken, how competitive the sector is during the time the decisions are being taken.
*Companies House is the British registrar of companies. In order to form a company legally within the UK you must register its name there along with several other mandatory details and pay a very modest annual fee for the privilege.